Right out of the "gamers are not very nice people" corner comes the Steam Review Watch, a blog where somebody collects the scathing critiques that games get on Steam together with the amount of time the reviewer spent playing that game. My favorite is the "Worst game I've every played" from the guy who played said game for 907 hours.
We have to consider two possibilities here. Either the people say the truth, or they lie. If they say the truth, and this really is the worst game ever, one has to wonder why it took that person 907 hours to find out. If he played the game for 20 hours per week, it took him nearly a year to realize that he hated the game! So the more likely explanation is that the reviewer lied. He did in fact have a lot of fun with this game, and played it every day for a long time because he liked it so much. And after 900 hours of the same game he kind of got bored. And he blamed the game for that, and decided to get revenge by posting a bad review. Lying is also quite likely the explanation for the review saying "2ez… finnished it in under 30mins" after spending 2,381 hours on the game.
I don't know how much these players paid for those game, but I don't see any games on Steam priced at a level where getting hundreds or thousands of hours of entertainment for your money wouldn't be a good investment. And if a game is really bad, I don't see how you couldn't notice after a relatively short time. Do these people really expect to be entertained for the rest of their lives for a $50 investment or so?