Easy, because what's apparently open code, isn't actually open code at all (see Hildon), but old code or only partially updated code that's sitting in a repo waiting for the go-ahead to release the real code.

Open is OK when things are actually open, but as it stands, half the "open" components out there are nothing of the sort. Then by the time they actually attain real open status again after a release Nokia is going to have moved on into maintenance mode and wont expend any effort on addressing community bugs and enhancement requests (not even, seemingly, when those bugs comes with perfectly good patches).

So, no, you can't have it both ways here. Either you actually do your development in the community by getting your developers and managers out and participating in the community and stop with the code-over-the-wall insanity or you end this "open" fiction.