(IE it's not an experimental product, it's not a product at all. It's just raphlinus releasing some code)
The question begged is Why does Google own the code?
To have Google give you (the Google employee) full copyright of projects you work on while at Google, you need to go through a committee[1] that reviews the project to make sure it doesn't collide with some other project Google already is working on. As this is really hard to do for many projects, it's easier to just let Google keep copyright ownership of it and have it opensource under them.
Considering how protective most companies are of IP, I'm shocked Google even has a mechanism by which a person can take back things they've worked on in office at Google.
It's actually a remarkably painless process, which is good because there's actually quite a bit of neat stuff in that neighbourhood of github as a result.