Different cultures and different people deal with this sort of stuff in different ways.

I wasn’t in NYC at the time, but I had been in the twin towers one month before the attack. I was working in London during the attack, my building for evacuated. Still, when I heard that a radio station had played “it’s raining men” during the attack, it was a big oof but also a very good if tasteless joke. And that was the same year!

The British have a great sense of humour for dealing with tragedy. After the 7/7 bombings, an old chap on the news was saying “I’ve been bombed by a better class of bastard than this”, and the next day office staff across the whole financial centre, at least, all lined the roads at 11am. Both in remembrance, and in defiance of the attackers.

Some people find stuff sacrosanct and feel it can’t be mentioned, let alone be the basis of a joke. And some feel humour is a way to humanise, process and deal with a tragedy. But let it be clear it is never mocking the tragedy or victims, it is usually looking for some funny angle on something inconsequential compared to the tragedy.

(Of course there are examples to the contrary, I’m giving an overall view of the reaction there at the time and since)