There is a certain genre of internet "humor" that goes along those lines -- "Why do German showerheads have 12 holes A) because Jews have 10 fingers" -- "Why are gorillas frowning A) because somebody told them they're evolving into blacks" -- "How many potatoes does it take to starve an Irishman A) zero." -- "What did the southern sheriff call the black man with 15 bullet holes in him A) worst case of suicide the county has ever seen."
...You get the idea. The intent isn't to target the specific group being "joked" about, but to shock the audience with a jarringly impolite punchline and thus bring a fit of giggles to the immature person telling the "joke."
Obviously you’ve never read first hand accounts of camp inmates during the Holocaust - kids being marched into gas chambers and burned in huge stacks. Over a million and a half children under the age of 17 were slaughtered. It takes some kind of insensitive person to see any humor in that picture.