" Refreshing, no question, and in direct contrast to Google and Apple as you point out."
Actually no it isn't in direct contrast.
When Apple first entered the mobile market they only had to worry about Blackberry, Wince, and Palm. In the smartphone market there was no real dominate player. It was in many ways a lot like the early days of micros with Atari, Apple, Commodore, Radioshack, Ti, and the CP/M machines fighting it out.
Apple and Google where friends and Google got Maps, search, and youtube on the iPhone.
When Android came out IOS was pretty much king. so Google kept putting their products on IOS to keep market share. Apple having the marketshare did not feel the need to put any services on Android. They used their services to keep market share.
Now Microsoft to get market share supports Android and IOS. Android and IOS see no reason to help Microsoft gain marketshare. It is the exact same pattern.