Why do some people hate mainstream bands?

Because there dumb.People think its cool to listen to a band that nobody knows about.But as soon as that band goes big they say they sold out and all they do write music that the radio wants to hear.But in retrospect every single artist wants to do that,every time you hear an artist say they just do it to express themselves or for the love of music that's really just propaganda for I to be a rockstar and make a lot of money.