The title says it all, and you are exactly right, MW2 does suck, because of epic failures like the one shown in this video. It gets real boring shooting these kind of epic failures when you know from the first shot he fires he isnt going to hit you, you could actually walk up, stick your shotgun in his chest and fire before he manages to hit you with that shit.
To blame a game for your failures is retarded. If you lack the skill needed to quick scope effectively, and this guy obviously does, try using it the way you should.