I think you are wrong on one account. It is more than a debate. it is the culmination of ALL the worldly experience that they have had, and their attempt to show it to everyone. No on has more experience in life than they do, which is why they KNOW all the right answers and you don't.
Challenge them and you will be attacked for it, because you just don't know what it is like to have the weighty world experience they have gained, through their extensive studies and lengthy discussions over a game on the X-Box, or an exprresso. Never mind that you have raised productive children. Never mind that you may have faced death in combat, or in the service of others. Never mind that you have made decision where making the wrong one would cost people their lives, or ultimately even have national security implications. It all doesn't matter, because "you just don't know what it is like".
I liken a conversion with these people to being responded back with a huff, a stomp of the foot, and a pouty lower lip.
Snot-nosed teens are notorious for whining "you just don't understand" when what's really occurring is the adult doesn't agree.
So it's important to recall that telling an opponent they are "ignorant" is to say they don't understand.