I mostly agree with your opinion about why Windows 8 was bad.
A full screen, searchable start menu isn't the worst thing - though it does mean I can't be read a webpage while looking for something (which is a slight loss on usability). This is just a special case of your point about only being able to do one (or two) things at a time, when on a desktop, I really want to be able to 4 or 5. It seems like an interface designed for a tablet stapled (badly) to a completely different interface.
Another problem is that they spread settings across 2 or 3 different places, hid things like shut down commands (because, you know, I'm never going to be shutting down my desktop!), and generally broke any consistency/sensibility to how the controls interface with the system.
> A full screen, searchable start menu isn't the worst thing
No, but it's a symptom of the worst thing. The worst thing is that Microsoft's UX team failed to realize that "The user's actually only interacting with this one thing right now" does not necessarily imply "This one thing is the only thing that deserves to even be visible right now."
A full screen, searchable start menu isn't the worst thing - though it does mean I can't be read a webpage while looking for something (which is a slight loss on usability). This is just a special case of your point about only being able to do one (or two) things at a time, when on a desktop, I really want to be able to 4 or 5. It seems like an interface designed for a tablet stapled (badly) to a completely different interface.
Another problem is that they spread settings across 2 or 3 different places, hid things like shut down commands (because, you know, I'm never going to be shutting down my desktop!), and generally broke any consistency/sensibility to how the controls interface with the system.