[vim_wannabe]

Most people just want an OS that keeps working for their stuff with the occasional security update.

WSL development for bringing in programmers as new users is nice and a feature that stays out of the way, but Microsoft wants to bring in tablet/phone users.

Universal apps so far seem kind of stupid, as an example Paint 3D is a single window only app. Pretty bonkers but I guess the API doesn't support multiple instances.

[WorldMaker]

You can open multiple instances of Calculator. Paint 3D running single-instance only is a design choice.

[megaman22]

The one that has been the bane of my existence is Lync/Skype for Business. So often, doing development or even just in mundane business scenarios, its worthwhile to be signed into multiple unfederated Lync pools at the same time, or just different accounts on the same pool.

I've worked with the underlying RTC libraries directly, or through the managed .NET wrapper, and there's no great technical reason for this; it's just that the Lync client has a global single-instance mutex.