I think YouTube has got pretty shit aswell, but more annoyingly it's ruined my favourite games...
COD, everyone knows every cheap tactic, OP weapon, camping spot, glitch, etc...
FIFA, KSI the wanker, 9/10 games you play online people will do a routine at kickoff that if done correctly cannot be defended against and you can be down 1-0 within 5 seconds, he's a funny guy, and in the past has made some excellent series, but most of his work is just teaching people to exploit the flaws in the game, the easy no skill way to win a game easily...
It's as if now nobody you play has any knowledge of the game of football and certainly no self respect to even try and play like real football... All because of YouTube!