Alas, "debate" on the Internet is anything but. I am happy to debate, even to see my ideas proven wrong by a person who is informed and debates with good intentions.

Instead, most of it is ill-informed, without willingness to learn, and for the last 12 months or so with a good helping of death threats, at least in my interactions.

And so, yes, we start avoiding disagreement, because the pain inflicted upon us is so intense. For better or worse, the Internet is failing miserably at fostering healthy debate. We have inadvertently created the tools that allow bullies to silence on a global level.

Or maybe it's just a regression to the mean - we've been physically disconnected from the rest of the world for most of history.

I don't avoid "debate" because I fear disagreement or attacks. I avoid "debate" because so often when I enter one, the person engaging with me immediately employs ad hominem attacks or strawmen or appeals to emotions or any number of other unconstructive argumentation techniques. I am tired of engaging people who cannot argue using logic or rationality. I avoid it because it will be tedius and draining and there is no hope against someone not using logic. (Obviously this whole statement is merely an anecdote, and I'm not trying to explain trends.)

I think debate is offensive/avoided these days because we have potential access to 'all' the information we could possibly need and therefore feel inadequate in a discussion where we can't look up things on the fly. Back in the good 'ol days you could debate without being interrupted to look up 'facts'