He actually likes half the games he reviews he's just very critical. Some of my favorite games of all time I could criticize to all hell and back. I'm not saying he's a troll or making stuff up, I'm saying he's a critic and does his job well. Knowing the flaws of a game is more important to me than knowing whether somebody has a biased like of a game.
Take for example his review of Smash Bros, his review was completely, totally honest and truthful, the game is a clusterfuck, they sold the game on the basis of characters who were difficult unlockables. It's ridiculous the way so much of the game was done and it's definitely an acquired taste, my first 5 hours of the game were spent loathing it until I could realize what was going on onscreen. The fact of the matter is I like Smash Bros but I can honestly say Yahtzees critical review was completely truthful and the points he made were fair and honest. People seem to think when somebody has a lot to criticize about a game that they hate it, to be honest most people can get past these criticisms, the point of reading a critical review is weighing up the bad and deciding if the game is for you. But the reviewer doesn't necessarily hate the game.
He did however hate Smash Bros, but most games he does like.