But, for my money, far more often people want to pretend that their dislike of something is somehow objectively true and then, when you point out that no, it's not actually objectively true, people then lose their poop.
It is extremely useful to remember that human behavior often has... understandable but not exactly rational underpinnings.
Speaking broadly, we have egos, and a sense of social status. Once we put a stake in the ground, failing to defend it can entail a perceived loss of social status in the community, or just a hit to the ego for being shown to be wrong. Some folks will go to great lengths to avoid those perceived negative results.
And, the worst part is that this is not generally a conscious reaction. We are often convinced we are arguing because we are "right", not because it feels bad to have to admit that we aren't right.