Thanks for the thoughtful post, Boris. I too have been a longtime Mac user, most recently the 13" MB Pro. I went through similar disappointments and explorations. As you know, I don’t get sales-y for one platform or another.
That said, Windows-based solutions might be more interesting now than they were before. The problem of “rot” that you described has gotten significantly better. The Signature Edition laptops at Microsoft retails stores eliminate crapware altogether, and Windows 10 is a significantly better long-haul proposition from a maintenance and rot perspective. I won’t go so far as to say it’s as good as OSX in those regards, but it’s substantially improved. And it’s the path to VR.
As I evaluate my own next options, I have both a loaded 13" Pro Touch Bar on order, and am working with a Surface Book right now. The experience on a device like this, while premium (and premiumly-priced), might be worth a review for you. Keep us posted, please!