I find that with most people that become large, they try to broaden their demographic by slowly changing their reactions with games and modifying their on camera personality.
While not necessarily a bad thing, as it widens the range at which people will enjoy watching their videos, it can alienate a lot of older viewers as well as they notice a drop in "quality" or performance.
Take in example Markiplier or Game Grumps. I used to an active subscriber to both of them watching almost next to everything they would upload, but as time went on, either them changing their on screen personalities or me just changing my tastes caused me to distance myself from them.
Any content I watch from them is now very specific stuff. I really enjoy the Sierra games the grumps pick up every now and then, and a lot of old classic games. And while I may not find the yelling and screaming all that entertaining, Markiplier does do nice videos right off the bat for some scary games which I find entertaining, and can talk about them intellectually for a fair amount of time for me to get a fair assessment.
I don't really hate the youtubers by the sort. I'm sure they're all great people, and would be fun to hang out with for a day, I'm just not a huge fan of their content, thus:
I don't watch it.