People sense things differently, naturally. We're different people is why. Sometimes that fact is not so apparent, however, until we disagree on the quality or value of something, which could be a movie, a song, a food, or an event, to list just a few. That's not to say there isn't always an objective moment or level to such things that lends itself to the more indisputable: the apprehending of a dangerous criminal, for instance, has a very good side on which most people would probably agree. The more subjective perspectives on the quality of anything are where "we have to agree to disagree", it's often said. Merely making a claim that Facebook is a "great" web site says more about the person making the claim being presently in a state of finding Facebook appealing than it does the value of Facebook, really. We say such things all the time, though: especially about foods, movies, and music. "How could you not like that? It's awesome!"
Our simplified notion of "taste" comes into play in such situations, literally or otherwise. As a means of opinion delivery, its real and complex basis whether we realize it or not is primal and involves smell, which is probably why we have such a difficult time defending any "taste" logically. "I just like it" or "That's how I feel", really, could be good enough, but in actuality for many people it's nearly impossible to understand and therefore acknowledge the validity of another person's preference for something for which they do not also have a preference. When enough people have a similar enough taste for something together in a place and time (a concert, a dinner, a theater) we feel it as a sense of community, and that feeling can be quite invigorating and vital for healthy living. (Relatedly, that's mostly why solitary confinement is a highly cruel punishment.) When a large number of people clash severely enough over some taste--especially one that tends to polarize people into two groups of either loving or hating the thing in question--interpersonal fights, group battles, and societal wars can take place and subsequently escalate.
We don't often place religion in the same category as music, videos, and food, but really religious preference is similar to those--especially if you're indoctrinated from an early age by your parents and other adults in your community--insofar as your taste for religion, if any, is a personal emotional tendency toward certain idea attachments which is almost always very hard to defend from an objective perspective regarding quality. Arguments over which religion is better, or over why some religion or all religion is best as opposed to atheism, inevitably retreat to articulating a defense of personal feelings and beliefs. "That's how I was raised, and that's what I believe." Saying anything to that effect in the final moment admits as much that you have little practical argument for why your religious preference is a good thing, other than that you believe it's good for you. At the start, people will usually posit something is good for everyone in some way, too, a rhetorical move to the universal that tries to pin the other person between either being dishonest or extremely unusual. That is, "If you don't like it, you're either not admitting you do or you're weird." In other words, I'm morally better than you because I'm enjoying this thing, this being within this moral community I've imagined that doesn't include you.
People with relatively rare but otherwise healthy preferences--unusual sexual kinks, strange tastes for food, a passion for unpopular music--usually have a more difficult time maintaining a feeling of self-worth and integrity than people who share preferences with large numbers of people in their society, regardless of the actual long-term, deeper healthiness of the widely-appreciated things, or lack thereof. The greater the present situation of feeling out of the group, of not enjoying what everyone else seems to be enjoying--among coworkers, in a classroom, at the family dinner table, in a movie theater, at a rock concert--the worse the sense of not belonging will be. An appropriate example of this is fast food. Depending on where and when you could be disparaging its value, you might get reactions from complete agreement among many (to an audience at a health food conference, say) to utter ostracization (to a group of people in a McDonald's restaurant line). Hobby groups are all about generating a sense of community, whatever its niche size and however temporary. An hour among like-minded people--birds of a feather--can have valuable effects on the self-esteem of people who do not share tastes otherwise with their larger society.
At the same time, tolerance of difference is a very important factor in the ongoing functioning of any social arrangement. Within the reasonable limits of sustainability, people work best together when anything goes and they accept and tolerate the distinct differences of one another. The relativity of tolerance, though, means that what might be acceptable in a group of people at a given time might not be acceptable later. In the American past, smoking tobacco around other people in enclosed spaces, even children, was largely viewed as an okay thing to do. It's as much a joking matter as a now bizarre truth that in the middle part of the 20th century, some general care physicians smoked around patients. As time has passed, we know, smoking tobacco has come to be less and less allowed indoors, legally and ethically. In the American future, according to this current trend trajectory, it will probably eventually be widely illegal and thoroughly unacceptable to do so around children in any setting. Of course, the objective level of an argument against tobacco smoking--that it pollutes the user's body and the bodies of those nearby with carcinogens and other poisons--has become more and more validated via disseminated scientific studies, which of course has contributed to the cessation and increased illegality of smoking. Before such studies were performed and while the pro-smoking capitalist propaganda was ubiquitous (before it became against federal law to use it in most media), in American culture it was not uncommon to believe that cigarettes, pipes, and cigars actually contributed to the health of users. Indeed, "taste" was essential to the mass marketing of tobacco products. Cigarette ads often touted smoking as tasteful activity, in more than one sense: a "refreshing" way to lose weight; an easy way to appear attractive; a method to "mellow", "calm", or "soothe" addled "nerves". (About the last, lest it go without mentioning that when organisms like people are addicted to a drug, their bodies typically respond to the low of being between highs with unpleasant "nervous" energy and react to the high of drug-taking with a sort of "calming" effect. Hence, the ads were effectively encouraging a vicious cycle in consumers purely to increase the monetary wealth of the companies selling the drug.)
Thus, the effective relativity of tolerance means less that anything can be good or bad depending on who or when you ask than it means that in a spatial and temporal way beliefs, tastes, and ideas change depending on how much enough people in a given community know and understand about their lives and the world in which their lives take place. Information is integral to forming and putting into action decisions that positively affect the health and long-term well-being of not only ourselves but also those around us in cascading effect. After ourselves, the people first in line (typically our spouses, children, coworkers, best friends, extended family--pretty much in that order, if applicable) are the first to benefit from any wealth of skillful knowledge on our part as well as the first to be harmed by any dearth of it. When we don't "know", when we lack information regarding what the effects actions of ours will be, serious and at once even unknown errors and damage can occur. People are blinded by ideology all the time like that. Even in the so called Information Age of the 21st century--even as the internet at this writing is beginning to come to wrist watches--some people seem to choose to make decisions based upon heavily subjective taste and their own historical preferences over the (for them) more challenging process of questioning, researching, and learning. Sometimes, otherwise apparently intelligent people succumb to pernicious, relatively common beliefs, purely for the sake of being comprehensive, the exploration of other options--that is, the tasting of something new.