Not saying Shorty is supposed to be Indy's son on a genetic level, but he was more of an adoptive son, and Spielberg could have gone a dozen good directions with that. Instead we've now got: "Here's Indy's Kid. Accept it."
Kinda like General Grievous. "I'm the bad guy running the whole Droid Army. Accept it."
Or Padme: "Even though there is absolutely no possible attraction that has been foreshadowed, I truly deeply love you. Accept it."