> The question is, is it necessary? Many systems can live with processes performing a little bit poorly for some minutes and I wouldn't do it.

The outage ain't resolved until things are back to operating normally.

If things aren't back to 100% healthy, could be I didn't truly find the root cause of the problem - in which case I'll probably be woken up again in 30 minutes when the problem comes back.

Desktops are not servers. There could be no problem, just some hungry legitimate program (or vm).