Well, upon closer inspection looks like polyphony stemmed out of Sony Japan. I'll take the L on that one. I'll remove Polyphony from my initial post.
Though that's one of several.
There are other examples. Media Molecule. They made one PS exclusive, LBP on the PS3, and were then bought by Sony. Their purchase, and others you listed, are much closer to being, as you said, "grown from the ground up" than the Obsidian purchase. Literally all of the acquisitions you referenced had closer ties to the company that bought them out than Obsidian would have to MS.
I could have been more diplomatic. It's been a chronic failing in the last few weeks. Wherever this goes from here, I'm sorry for being a dick.
- "If you have the heart of a true winner, you can always get more pissed off than some other asshole."