Depends on Context.
Obvious Statement: Tragedy is bad, but jokes are not. And as more time passes, it allows us to be more removed & objective with a tragedy. Yes 9/11 is still bad, but there is an eventual point where tragedies no-longer are taboos to joke about. I think it's funny that South Park arbitrarily put the 22.3 year date - obviously no date is set in stone.
Does anyone nowadays shed tears for the tragedies that Genghis Khan committed? Why... TIME. Maybe the timetable is much longer than 22.3 years, but there will come a point where it'll be joked about and no-one bats an eye.
Something about glass houses and stones.
I mean I go to your profile, and you act like a porn addict.