I hate to say it, but it's the crux of the issue.
Take Global Warming, for example. The evidence is overwhelming now. Yet Conservative still cling on. Not with facts, logic, or reason. Not with anything worth discussing, or rising to the level of an actual debate. Discussion requires a certain intellectual effort. It requires two sides to have a conversation. Yet all we get from most opponents is an outburst of feelings. Few among them possess the time, energy, or skill to turn something like Global Warming, where they have zero evidence, into a debate with a counter argument.
It only gets worse from there, on subjects of more complexity. Such as the economy. And how we'll manage it with increasing automation.
One theme I've heard from a Trump supporter is essentially "burn it all down" and shove us back into an agrarian society so each person can "feed themselves". All so they can hold onto the mythos of "each man an island" and "bootstraps" will provide. It seems, to me, to be a complete mental breakdown and inability to process the information provided. So the person wants to crawl back to a time where things sounded simple, and "freedom" was maximized. Even if that means a horrific, violent, diseased, and short-lived life. They think living in the 1800s is better than interdependence on other people. Even though the great flaw of that argument is, the height of agrarian society involved a great deal of trade and economy.
Go figure. The one thing this person wants to run away from, they don't even comprehend that it's still necessary to achieve productivity.
Questions of hostility aside, the sad fact is they've usually got nothing to provide. Even when such an effort is put in, they'll be buried under 10x-20x the response. Most of which is not going to be constructive. Who has the time, energy, or skill to keep up with all that? What little there is, we chase away. I'd think of it like people of two languages trying to sit down and reach an understanding. Even if the two people could focus and give it an honest attempt with each other, they've got an entire tribe of children running around and screaming in their ears. It's not likely to work, or encourage an attempt.
Mostly, we are left with those of a much similar language, who largely understand each other, and still have things we disagree on.