Might be nice if there's the ability to "lock" an installation against deletion which must be manually removed to guard against accidental or careless deletion of installations.
Some people (not me, of course) rush things they do regularly and don't always pay the full attention required to certain tasks. I'm sure that one day I'll rush and delete a whole installation I didn't mean to.
I know MailChimp use the method of forcing you to type "DELETE" for certain tasks which usually prompts a quick mental check of what it is you're deleting.