Offensive because you're respectful and serious and you remember. Survivors are still living. Not everybody is so respectful, not nearly so pc. They don't see the problem. They don't understand. They reject censoring and censuring. Some people in the offensively distasteful 9-11 advertisements do not or cannot feel what you feel. They cannot comprehend lingering trauma. They don't understand why we're not over it, why we must behave, and behave for so long. Some were children and did not understand, too unaware of the importance, noncomprehending of grief. Too remote from events to comprehend why jokes are inappropriate. Worse when you weren't even born when the events occurred so pre-history to them. Like WWII to us. To them it's like accepting a joke about Pompeii, Sodom and Gomorrah, Iram of Ubar, Galveston Texas, Valparaiso Chile, Haiti, San Francisco California, Sumatra Indonesia and other cities destroyed by tsunamis, Pearl Harbor and Dresden, Titanic, for examples. Jokes about these events may or may not be acceptable to you. You might be able to participate in the black humor. You might even find them funny.
These mushrooms were submitted by b3ta member Barbarossa to "souvenirs" challenge. Front paged submission include this snow globe. A lot of disastrous snow globes, actually.
See, it's just dumb. Penguins are South Pole animals, the submitter didn't know that. Introduced with "Their snow globes get worse every year."
Should your heart carry a streak of black humor you might find the perverse souvenirs funny. T-Shirt from Aliens, Auschwitz oven mitts, (misspelled there), toy truck from Nice France, 9-11 spaghetti and sauce, Auschwitz again, boys striped pajamas in front of baby gate, Donald Trump (a disaster in their political world view as born socialists) doll holding a cheese grater, Trump again, (see? obsessed with American politics) same doll holding an AR-15. Twenty-one such examples of bleak humor. This is right up their alley.
You'd be surprised and no doubt aggrieved and dismayed by the number of of 9-11 jokes posted on that site. It takes a strong stomach and very thick skin.