In theory, yes.
In practice, first, not every fix would be accepted.
Second, as for me, I'm busy enough with my own stuff to do this.
Shouldn't Google be interested in fixing at least some of the most insidious bugs?
It's their product, isn't it? And the affect developer and user experience.
On features - speaking of WebView, there was a storm of comments in the bug tracker, pretty much all of them were closed with "won't fix, working as expected", which really means "Gmail works fine, Chrome works fine, the rest is someone else's problem".
And before someone says that Android is free -- don't know about others, but I've paid a lot for my "stable" of devices.