"Logical inference is simply insufficient."Untrue. The impression comes from the extra-large volume of crud available in the field. Due diligence here is especially strict. Add in the population of bullshitters who aren't even trying to get it right...and logical reasoning gets a PR problem.
I find this particular statement ironic, though.
"which is ~90% of the time unjustifiable."Why is it unjustifiable? Under what framework?
"There's only those 2 choices when any reasonable fraction of folks disagree : they're ALL stupid, underinformed, or evil, or you might well be wrong. "And here's a straightforward logical inference being used, including the principle of excluded middle.
I'm epistemically privileged because I've spent well over a decade intensively studying epistemology.
"Then what makes you think you sit in a privileged epistemological position?"
An interesting property of advanced epistemology is that if I'm doing it right, I must necessarily get answers frequently different than everyone else. If I get the same answer it should frequently be for different reasons. Prima facie it is indistinguishable from being a crank.
"Then why don't you take your opponents positions (not their arguments) more seriously?"An interesting thing about ratiocination is that you must be able to answer every argument. If your thinking is actually solid, then you should be able to find the contradictions in all opposing arguments. (This is not as huge a task as it seems. New arguments are many order of magnitude rarer than arguments trying to appear new.)
But clarity of communication is on average...not good. Do you want to miss the killer counter-argument because it was difficult to parse? Therefore, epistemology effectively teaches a form of hermeneutics.
Running around practising this hermeneutics regularly, I learned something that should have been obvious - positions must generally be consistent with the holder's daily experience. As much as biases can deflect us from truth, it is harder for the bias to activate every day than it is to simply accept the truth. I suspect a lot of religious hypocrisy comes from this - daily truths are acknowledged, so that the adherent can effectively go about their day, and only have to spin up the biases in the rarer, specifically theological situations.
So already there's two categories - closely following Hanson's near/far mode categorization. It is easy, indeed common for far positions to have no basis in reality whatsoever. You can safely ignore all of them. (Things tagged 'speculation' are usually in this category.) The purpose of this kind of position is not to be accurate. Its usefulness is in building alliances.
If you can determine that a position is interacting with someone's daily life, and contradicts your position, it cannot be so easily dismissed, regardless of the quality of arguments the holder can render in its favour. The truth must be consistent with their experiences. So is your position's consistency non-obvious to your opponent? Are their far-mode positions contaminating the discourse? Are you failing to communicate well? Did you piss them off and they're opposing you out of spite?
If not any of the above, the most likely explanation is that they have data you don't, that they are familiar with situations novel to you, and they are inconsistent with your hypothesis.
Together it means, subject to the caveats detailed above, you must have an answer to every counter-argument, and a position by itself is a form of argument.