When you see a game that ask you to log in to your game center or open feint account, do you click “OK”, or do you just skip it?
I use it, but for the most part games seem to automatically log you in and not bother to ask you if you want to log in.
Overall, I think it’s a good thing to include it. It’s another marketing tool. When you log in you will be shown icons for other games, and while browsing achievements you can compare yourself to your friends and see what they are playing, a bit of an automatic word of mouth.