I feel like this is bound to happen anytime you're optimizing for ease of development rather than user experience. Same reason to beware of cross-platform UI frameworks.

But for Facebook, at this point perhaps their users are so entrenched that the app just has to work, however lackluster it may be. On the other hand, between this and the Python thing, I just can't understand why FB seems so stingy with its dev resources. I realize there is a lot of ground to cover but this is one of the biggest companies in tech we're talking about.