You don't understand what parent comment is saying ... it complains Apple's closed environment not allowing of any apps to be installed in anyone's phone unless app is downloaded from AppStore.

I don't think anybody's suggesting that Facebook should be an exception - rather, it would be good if Apple allowed everybody to sideload iphone apps (other than enterprise and developer keys, which are both great for their niche but not general-purpose)

Apple should offer an alternative way to load apps onto the phones that Facebook paid for that can't be revoked.