>>88348384People are petty, and will exaggerate their grievances to assuage their anger because they're too ashamed to admit that they're getting worked up over something inconsequential. To people like this the mere fact that Filian is more popular than them, or their favorite vtuber, is enough to make Filian public enemy #1 in their eyes. People get angry when they feel like one of their needs isn't getting met. In this case they need to feel like they have good taste, or they need to feel like they haven't wasted their time, so the idea that something they genuinely like isn't popular makes them insecure and subsequently angry. It's a feminine mindset. For men disliking a popular thing, or liking a popular thing, doesn't cause cognitive dissonance. Confident men tend to judge things they're interested in on a case by case basis and its popularity is less important. Whereas women or insecure men are instinctively pressured to only accept the consensus as correct. When this instinct and their desire contradict one another this creates turmoil inside them, and the only realistic thing they can do to silence that turmoil is to put effort into convincing people that popular thing is bad.
tl;dr: They're stupid bitches.