Indeed. The "Open Source" aspects of those companies are more to do with trying to diminish the value of their competitors.
It's a case of "Everything I do is valuable, but everything you do should be free."
It's a case of "Everything I do is valuable, but everything you do should be free."
Why should they? It would be nice if they did but they'd be directly enabling their competition. That's not what open source is all about as far as I understand it.