Lets cast our minds back to when Heelys were popular and iOS had opened the app store, everyone collectively held their breath for the Facebook app. And it was good. In fact it was a shining light of why native apps were so good, it was smooth and fluid. There was bugs, it was a new thing without a lot of time in the field but they improved with every version.
Skip forward 3 years and remove Joe Hewitt, in an attempt to simply their development portfolio the Facebook app is everything it shouldn't be. It's slow, it's glitchy, occasionally when you tap something it'll decide that you've requested something completely different. At the end of the day a company needs to simplify development eventually, but not at the expense of crippling their application.