I took care of my SIL and her children when she was down with the flu. I hauled over several jars of homemade chicken stock and made her chicken soup, and served the kids some, too.
Her oldest was in fifth or sixth grade, and he was the whiniest little rude thing about the whole thing. “Just try it. Eat one bite, that’s all I’m asking.” But it didn’t matter-- he flat-out refused and whined and was such a pathetic baby. His younger sibling wasn’t any better, and the youngest sibling at least ate a few mouthfuls before he abandoned it.
Their pantry is full of processed food and junk. She doesn’t like making her kids do stuff they don’t want to do— and I’m not the only one who’s been offended when you try to do something nice and thoughtful, and they turn your hard work into trash.
–edit-- It just occurred to me, I know other people who have hosted my SIL have commented on her own poor grace at trying unfamiliar food. Not unfamiliar food like, say, balut or something else likely to make an appearance on “Bizarre Foods”, but ordinary food, like bouef bourguignon. So her own habits are definitely reflected/magnified in her kids.
I have a friend. He’s a grown man, ex-military, everything. He is a total baby if a vegetable even touches his plate. It was almost embarrassing to eat with him in a restaurant.
So— my guess is, people never learn, until they learn that eating x is preferable to the social stigma of being ungrateful about the food your’e served. And in the case of my adult friend, he’s got too much self-confidence to be susceptible to social stigma.
Me, I was raised that if I didn’t eat it for dinner, I’d be seeing it again at the next meal. And the next meal. And however long it took. But my husband doesn’t like the conflict at the table that goes along with making kids cooperate. So I’m not able to be as strict as I’d like with my kids. And they end up being rude and ungrateful periodically, and it embarrasses me— because whether I’m the one on the receiving end, or even worse, someone else is, that’s just not acceptable behavior. But the older one is gradually maturing a bit, and is getting better at eating what’s in front of him, but he still occasionally forgets that he likes x, y, and z and will kick up a fuss over things that he liked the last time they were served.