Casey's a really smart person, who contributes a lot to the indie gaming scene, I have a lot of respect for him. But this rant of his you've linked to isn't really meaningful to this discussion.
1) Half of this rant is complaining about how terrible Razer is as a company. Razer's software and hardware problems are well known and well documented, none of that is Microsoft's fault.
2) "Pop-ups during gameplay" is part of what you get from having an open operating system. Sure, it might sound nice for Windows to ban anything from interrupting gameplay (as Casey says, "no gamer would ever accept a popup during gameplay -- it's absurd to even consider").
But people really do want that. Removing it would mean you can't get incoming call alerts (Skype), it would mean VoIP indicators couldn't warn you if you are/arent on a hot mike, it would mean you can't use the Steam in-game overlay, it would mean you could never have FPS counters or software-based screen recorders (like FRAPS), and so on. All of that is useful to one user, and "annoying popup spam shit over my game" to another user.
Microsoft actually tried to block popups over gameplay in UWP and PC gamers rejected it specifically because it prevented popups from Steam / Fraps / Nvidia / AMD from running overtop of games - https://arstechnica.com/gaming/2016/02/microsoft-needs-to-st...
Windows has to straddle this line of being a somewhat open operating system, while appreciating that 95% of it's userbase will intentionally break their computer and blame it on Microsoft when given the power of an open operating system. If Windows let average folks easily disable updates, for instance, lots of people would do it and then break their computers, or complain about Windows getting "viruses" or getting "hacked". That's not just conjecture, we have over twenty years of computing history where Microsoft tried to trust users to update on their own, with dire consequences. (See WannaCry https://www.telegraph.co.uk/news/2017/05/13/nhs-cyber-attack... where Microsoft fixed the vulnerability before it could be exploited, but users blocked/delayed the security update containing the fix)
This rant also drastically underestimating how much effort goes into making Windows work. Does anyone remember Sony's PS3 + Linux fiasco? Sony literally could not flip a switch and have a Windows PC competitor out the door "tomorrow", the idea alone is ridiculous, and drastically undervalues the work required in operating systems.