Why were the people at 9/11 mad? They ordered a Peperoni Pizza but only got a Plane!
Are you making light of 9/11?
But people said it was funny, your opinion isn't authoritative about what is and what isn't.
You shouldn't be trivializing the victims of 9/11. It was a horrific event and I don't think you are helping in any way. I suggest watched a documentary about it and learning why it was so bad.