"real serious conversations about difficult topics are near impossible."
Basic conversations about basic things are almost impossible.
Sciency/hackery software devs are a unique breed, we like to talk, debate, consider. To everyone else it's just 'disagreeable'.
Making people like and respect you is sadly, the only way to get most people to agree with you.
The most important 'tactic' when trying to get people to agree with you is ... to be tall, slightly good looking, reasonably well kept, and for the other person to believe you are listening to them, and that you agree with them maybe about 'some issue' but more importantly about some deeply held value they have. Then you are 'right' about whatever it is you are supposed to be talking about.
In other words, it's not about facts, but about relationships, which is why so much of sales is about that, and not product/price.
For some reason humans are really, really bad at objectivity and I think we information nerds are only just a little bit better than the rest.