Why are people so hard on certain bands?

I don't know, I mean sometimes I go on youtube and I hear these amazing bands, and people on there are so hard on them, claiming their vocals suck, when they are enthralling, that the lyrics suck, when they are amazing, etc, etc. It's ridiculous, I swear some people are just so hard to please, almost as if they are impossible to impress or move. Why can't people just enjoy the videos without having to be such critics? Especially considering that they themselves cannot even come close to producing music of any good quality. It's like, music can't just be amazing anymore, it has to sound like a heavenly choir with god himself as the conductor. I believe that musicians are held to far too high of standards these days.