Agreed - you assume that 1. Everyone is on Facebook 2. Everyone on Facebook has friends with iphones/ipod touches 3. That everyone will also buy and play the same games 4. That everyone loves the big blue button that gets stuck in games 5. That everyone cares about highscores. Bury it deep in a menu as an option maybe and only then if Yes display a button. That blue button can make some game pages look ugly too.
I wish everyone would be able to dock to CloudCell. The Online Leader Boards and game specific online stuff like in Real Racing with a website and youtube integration are so much better than what Plus+ or OpenFeint offer.