However, the problem with Win32 programs is that they aren’t written as “Universal Windows Platform”(UWP) apps, which makes them much less portable.
UWP apps are NOT universal. They LOCK YOU INto the Windows 10 platform. The only thing "universal" about it is it is supposed to allow you to use it on any Windows 10 (and its flavors for XBox, Tablet, or Phone) platform. As a developer, it locks you into their tools as well. Currently MS still is supporting Windows 7, 8, and 8.1... UWP will not run on those systems. period.
Microsoft's ultimate goal of getting all Windows users to use only UWP apps does not sit well with some game developers, who think Microsoft will restrict them from the platform.
Microsoft
could get nasty again easily enough, especially if they think they can get away with it. How many remember the Windows Certified" program they had a couple decades or so back? Remember Microsoft had a tendency to NOT issue the certification if the developer also developed a version for another OS? It could go the same here... "Oh dear, I see you develop for Playstation..." "Oh dear, I see you develop for Linux...", etc. All they'd have to do is lock everything into their app store, and there goes GOG, UPLAY, ORIGIN, STEAM, etc... all in the name of "security".... yeah more like security in getting their hands in everyone else's publishing and developing business.
The lock into a specific "owned" folder for the app won't fly very well in the business world either where one app may listen in on a server, grab files and then send them off to another app to process them into different formats. Anyone ever look at the Electronic Data Interchange formats out there? Anyone store their data files on some other drive than where the OS is installed?
I also guarantee it will NOT stop malicious software. Java promised that in the beginning, now... it fails miserably, and in some cases even runs horribly slow. Apple's Walled Garden, even with its examinations and testing for approval to be included, still has security issues with the apps it offers. You can even see problems within the Android Store too.
No, this is just another power-play from Microsoft disguised as "protection for the masses who are just too stupid to know what they want or to know what they are doing." And... anyone that isn't them is part of "the masses."