Yes, of course. Is the common scenario in all old-school linux users and had saved me a lot of headaches. It simply works.

> Why recover a system like that when I can just boot off a USB stick?

Because I can. The basic parts of the system are still available and working. I don't need to reboot to fix the problem, I could mount a different and working /usr in seconds. Is not just "a hack", is a design.