Zuckerberg has a higher hit to miss ratio, it's true, but don't for one moment think that Facebook does a great job of acquiring smaller companies. You only have to look at Parse to see that even Facebook just can't seem to do it well.
Slightly off topic but I'd say the way Parse was handled was pretty good.
Not off topic at all :-) I have no real knowledge about why Parse failed other than what has already been written. In fact, your comment is probably fair and nothing I said above applies to this situation. Sometimes takeovers just fail, and nobody is to blame. It's just that, IMO, it's very rare this occurs.