Seriously, if I pay $50 for a game that takes me five hours to complete, I'm not just going to play through it again to unlock some shitty artwork. I want REAL meat and potatoes for my money, and more so if I'm going to keep playing it.
I'm looking at you, The Simpsons Game. Sure, it's a couple years old, but I paid $50 for it when it first came out. The controls made the game nearly unplayable, but hell, the script was funny, so I persisted. I beat the game, and now it's been sitting on a shelf ever since. The point is that unlocking the stupid "cliches" and other assorted crap wasn't enough to make me ever want to play that game again. And this is an increasing attitude with game developers. To charge full price for a game that takes me only a couple of hours to beat, and then add "replay" value by telling me to spend a few more minutes collecting stupid crap so I can see lame sketches of the characters they made. Along with the attitude that it's okay to ship games out with insane bugs (lol Sims 3) as long as you plan on patching it later, game developers are taking their market for granted.