What you say is largely true and with two important topics in particular: political and religious / spiritual beliefs.
The saddest part is that this behavior of “the way our family sees it is right and don’t bother to ask those other people what they think,” is too often encouraged and ingrained by people’s parents at a young age. So the kids go straight from curiosity to know-it-all (see also: know nothing) because the parents are afraid to let their kids figure the details out for themselves.
And the great irony here, is that these are the areas where the kids literally could figure it out for themselves, unlike physics equations or financial spreadsheets or whatever else you can think of that is purely an “adult thing,” which has to be taught to a person as they go through school.
So the one area where a young person could explore their own ideas and readings and have their own thoughts on the matter be just as valid as their parents’ thoughts (read: both parties are a farce, zero people have a hotline to God, 100% of religious origins stories are full of holes that even a kid could deduce given a little time, all mainstream religions have some ugly history that kids could learn about as well as the happy sun-shine version their parents feed them)… all that is stifled because Mom and Dad feel more warm and fuzzy by spoon-feeding their kids “the truth” and then discouraging any contradiction of that truth.