Tournaments have extremely high variance. To put it into perspective how difficult it is to win a tournament, say you play almost flawlessly. You go all-in 10 times as an 80% favorite, but instead of running the cards, you pull a chip out of a hat blind folded to determine whether win the hand or bust. There are 8 red chips and 2 black chips. You pull one of the black chips out, you go home. You have an 80% chance of pulling out a red chip. It doesn't take a math professor to see that even if you go all in ten times as a gigantic favorite in the poker world, chances are you're going to pull one of those 2 black chips out eventually and go to the rail. Reality of it is, you're going to be faced with thinner situations than that throughout a tournament. You want people making mistakes. If there were no mistakes, the only entity making money in poker would be the house.