Why do people hate achievement

Rooster Teeth has done some great shows and other entertaining content, of which I really enjoy. However, when you watch the podcasts, the people themselves often come off as pretentious and douchie. Burnie Burns, in particular, seems to have this "superiority" attitude when he discusses certain topics. When he's called out on contradictions to his statements or that he is incorrect in some way, he simply responds, "Shut the f*** up." rather than simply apologizing for his mistake. Burnie is also quite inconsistent when it comes to people who've found fame on Youtube. He'll defend Justin Beiber, but hate on Pewdiepie.

I'm not saying Rooster Teeth isn't talented, they've got the content and fanbase to prove it. However, they're not the kind of people I'd want to go hang out with in person, based on how they present themselves in the podcasts. I'm not sure why they'd be jealous of Pewdiepie since they're very successful, but I'm curious why they single him out versus other popular Youtubers.