It's good that many people aren't having money trouble, but that's not really the issue. All this currency system does is hurt some peoples experience with the game. It doesn't add anything to anyone, it just takes away from some. If that's not enough reason for it to go, then I don't know what else to say. For those of you not having money problems, it wouldn't affect you if the whole currency system disappeared, so why not remove it if it helps others?
The Facebook app in and of itself doesn't even sound like that big a deal, it's the currency part of it that's the problem. Someone in another thread mentioned using it as a friend's list extension. Perhaps an uncommon issue, but perfectly valid. Without the currency stuff, it's harmless to those who don't want to use it.