It's also disturbing that one of the most successful businessmen is introspective and learns from mistakes?
It's telling that marketing / branding / repuation doesn't factor into his internal model of Android vs. Windows phone.
At the time, google was doing a good job of branding itself ("do no evil") as an open, transparent (at least in terms of source code) and interoperable member of the community.
(oh how times / perceptions have changed...)
So google and had a lot of good faith with developers who were unhappy with Microsoft's ethics/business practices, browser war schennanigans, etc...
This played no small role in Android's early adoption and ultimate success.
Linux had a different name. Arguably, a better one. One of the weaknesses was software compatibility and UI complexity. Android didn't suffer from the former (as all of that was fixed before phone shipped), and tried to limit the latter with a new UI from the ground up (no X/KDE/GNOME etc).
Companies such as Google and Facebook take security serious. Because they're data driven companies, they want to protect that vehemently.
Once the pieces of the pie are cut out, its extremely hard to get even a small part of the pie. Linux desktop was too late, Windows Phone was too late. Why? Apps/ecosystem. I mean, Windows to this date still barely has a way to update software like Linux had for more than 20 years (APT, for example). You need either Windows Store or a third party one such as Chocolatey or Scoop.