Of course Microsoft does have some large strategic goals for its public conduct, but is it really such a stretch to allow that the Azure team wants to embrace developers outside of their traditional base? So long as it doesn't conflict severely with some other goal of the company, I don't find it difficult to believe that an enterprising manager on a mission could push through a project like this. Interoperating with a fledgling open source project for mutual benefit, even though it might not be a traditional tactic employed by Microsoft, is certainly not a particularly hard pitch to sell. Particularly if it's not a heavily politicized open source project.
For example, let's not forget that both Microsoft and Google donate millions each year for academic research into computing -- stuff that is way far out, such as trying to find viable quantum computers. These companies have giant market caps, and even though Microsoft may have a corporate edict to stamp out Linux wherever possible, and Google's profits are directly affected by how much creepy info they can gather on you, these companies are made up of a bunch of humans, and you have to expect that at least a few of them can scrape together altruistic and benevolent projects.
But, WP7 demands an SL/XNA and .NET background. It seems like reaching non-Microsoft developers was/is a tall order whereas iOS can tolerate C,C++ or PhoneGap solutions. Do you feel that Microsoft had some success in bringing people into the tent?
I can't speak for the Azure folks, but I can tell you that as we built WP7 we recognized that one of our biggest challenges was reaching the hearts & minds of developers who had grown up outside the "MSDN tent". It was very clear (to me anyway) that we had to try extraordinary things to engage with those developers.
I suspect the Azure team is thinking the same way. It's pretty clear that being insular isn't going to work anymore.