I'm not a huge fan of lag switching, it does interfere with other people's game-play.
Though, the video was a an extreme example.
As far as, people being level 15 and what not. That doesn't impact other people's game, sure they (legit players) will get bent about getting there by boosting or glitching. Seriously though, the average person will not get prestige 15 before MW3. By, then no one will care.