I've always assumed that the acquisition failed horribly. The apps are still the same code as pre-acquisition, and I'll bet a lot of the original developers left pretty sharpish. It's quite possible that the original codebase is an absolute train wreck, it's not as if it was ever an amazing app, after all.

I wonder if MS acquired Skype today (i.e. "The New Microsoft") whether they'd have been more successful.