Why should they be "cleaned up" when there are TLDs like .blog, .hotel, .sucks, and other great ones (.great doesn't exist) that are allowed to be there?
Or rather for squatting. google.sucks is registered by Google LLC, microsoft.sucks by Microsoft Corporation, meta.sucks by Meta Platforms, Inc., and so on...
That's what the rule says. But of course, such rules are arbitrary and can be changed.
ICANN could delist in theory, that peacekeeping makes it impractical.