I could justify it a number of ways, but the honest answer is "expiring these is more work that just hasn't been needed yet". We hit a handful of bad actors, banned them, have heard no negative outcomes, and there's really little indication of the behaviour changing. Unless something shows up and changes the equation, right now it looks like "extra effort to invite the bad actors back to do bad things" and... my day is already busy enough.
I could justify it a number of ways, but the honest answer is "expiring these is more work that just hasn't been needed yet". We hit a handful of bad actors, banned them, have heard no negative outcomes, and there's really little indication of the behaviour changing. Unless something shows up and changes the equation, right now it looks like "extra effort to invite the bad actors back to do bad things" and... my day is already busy enough.