You can also distribute classic win32 apps with MSIX as well
I really hate worrying what an App like Chrome is doing to my system and I'm reminded every time I launch it because all my Thunderbolt connected monitors black out for a second when it starts up.
It doesn't stop Win32 apps from doing crazy Win32 things (unfortunately), but it's still a step up from MSI/EXE installs in general.
This is a good thing, and it makes MSIX a usable packaging format for pretty much any application under the sun - but nobody should assume a MSIX package is safe just because it’s a MSIX package.
I see current MSIX limitations for Win32 just as means to incrementally steer developers into it, while not introducing too many breaking changes (as WinRT happened to be).