But there's a difference between intentionally removing components and thus removing the functionality they bring, and breaking things. So you CAN remove all those apps if you don't need any of their functionality (which implies that you also know what each app does). If you know what you're removing and you want it that way then it's not broken for you. If there are side effects that you don't want then it's not broken, it's just something you didn't expect. When removing them with dism/ps then you only do operations that are permitted. And I'd even say that apps that are locked but still can be removed with some registry trick also fall under this. When doing things like that your OS and other things that don't rely on the removed things will keep working, sfc /scannow won't complan, no crashes or instabilities, then it's not broken. So brainlessly removing all apps, then noticing that you don't have start anymore and thinking "oh s**t, I broke it" isn't braking it. It's just uninstalling the start functionality, through a legitimate way, as you requested it.
If you read my post earlier above correctly, you'll see that moving core components to the Windows Store implies that choice. Remember when Microsoft was required to add a browser ballot due to EU antitrust sanctions, even up to the point of nearly releasing editions of Windows without IE (E Editions). Why is this relevant, you'd ask? Think of it more broadly, what if EU would require Microsoft to do the same with other components of the OS? Let the user choice between default and third-party Calculator, Calendar, Paint, WordPad... By moving core apps to Store, they can update them easier as needed, as well if users will see core apps updateable in Store, they will see other apps too, so that antitrust scenario gets eliminated. If there would be a choice between Modern and non-Modern, be sure users would stick with the latter, due to users hardly taking new technologies. When Windows 95 was released, everyone complained about Start and continued to use Windows 3.x. When Windows 1.0 was released, everyone still was sticking to DOS. Nowadays we see the same situation, where Microsoft slowly shifts over to Windows Runtime and end compatibility with decades old code, but users denying it favoring old habits of using Win32s.
I don't know for all of them, but for example the camera app can't be removed but IIRC you could change something in a manifest and dism will just remove it.