Earlier quoted context omitted.
Microsoft has a history of creating new UI frameworks. IMHO it's the result of Ballmer's "Developers, developers, developers!" attitude, which I think is a good thing at core (court the developers that add value to your platform!) But this results in chasing a new paradigm every few years to elicit new excitement from the developers. It'll always be more newsworthy to bring in a new framework than add incremental fix…
I think the reason they keep trying new UI frameworks is that no one really adopts them. Developers know that Microsoft won’t kill off backward compatibility and break all the enterprise apps, so why rewrite? When one framework fails, they start working on the next one. I question if they understand the corner they’ve painted themselves into.
my Windows API knowledge (essentially: just Win32) is still exactly as useful as it was then, having missed the 7 or 8 different UI frameworks in the interim