Most people are mildly authoritarian, they do not just wish to leave you alone. It's natural, even if not wise, for people to try to remove or influence things they fear or do not like, no matter how much impact they do on them.
There's a reason moralfags, for example, are so crazy about their morals - they treat the resistance as a personal attack directed to them, so they try to force you to at least act the way so you do not scare them or cause the discomfort, especially when they have no means to enforce the actual rules.
Democracy is so popular because it exploits and feeds on these feelings, which are never in short supply when people's opinions are left as they are and protected, without chance of competing, and i'm not talking about eugenics here.
The lefitst class struggle is also about that, as it assumes that people are competing for power withing political parties as part of the state, and in that system it is true, as peoples' interests do interfere there, what it misses is that people often operate without the state and not as parts of shifting and all consuming state body fighting within itself for influence, as all individuals have generally common interests, no matter their wealth.