Earlier quoted context omitted.
What conspiracy theory? The vendor lock-in behavior of MS is practically advertised as a platform feature. To up and reverse their product lock-in policy would cast doubt on many (most?) of their other claims.
The conspiracy theory is that they want to lock you in for no other reason but to give you no other viable option. That's absurd. They want to sell you as much software as possible, of course, they're a company. But the reason they will stay in the mobile space isn't to keep you from getting any other mobile device. But because there's money to be made in it and it fits into their core competency.
Hell, they even invented the slogan "Embrace, Extend, Extinguish".