Well, “X is offensive” is not something I'd normally say -- I'd specify who is offended (e.g. “I'm offended by X”, or “X might offend [class of people]”), even though sometimes “[class of people]” is as generic as “someone”.

Fair enough, but it's not obvious that the mere fact of someone being offended is something I (or "we") should care about.

I noted here that

[W]hether we as a society agree that the target is entitled to take offense seems like the straightforward operationalization of implementing the two-place function of offense as a one-place function. So when I say "I don't think X should be considered offensive", I'm not making any sort of claim about whether any particular person will in fact take offense; the claim I am making is something along the lines of "we should not consider offense taken at X to be justified, and we should not care about said offense, or modify our behavior (i.e. stop saying X) on the basis of said offense".

As for fixing the listener's deficiencies...

You mean in principle or in practice?

Well, here's the thing. Let's say I say something to someone, or a group of someones, that this person(s) finds offensive. Let's say it's the case that in principle, the situation would be fixed (that is, the offense obviated) by suitably "fixing" the listener, but in practice this is not feasible.

The question still remains: did I do anything wrong? If so, what?

Well, I might plausibly be guilty of not knowing my audience. That's an important skill to have and use. Some people, though, seem to behave as though any instance of a speaker saying something that is offensive to anyone who (by intent or otherwise) hears it, constitutes a horrible crime on the part of the speaker, and not only is inherently terrible, but reveals personal evil.

And my response is: no, if this offense would not have happened but for the listener's stupidity or insanity, then all that's happened here is that the speaker might have to exercise more caution on what to say to whom. We should not throw our social approval behind the listener's offense (which is what we seem to mean in practice when we label utterances as "offensive"). We should not demand groveling public apologies, excoriate the speaker for being a terrible person, demand that he/she never say such things again, kick him out of our club, demand that policies be put in place to prevent such horrible things from being said ever again, etc. etc.

Because there's always going to be someone who is sufficiently stupid or insane to be offended by virtually anything. And when that "anything" happens to be the truth, then by socially approving the offense taken, we create an environment where the truth (even if it's only a specific subset of the truth) is less likely to be spoken. That is a great loss.

And here's the minor quibble:

I would say 75-95% of all white, male, fathers in the United States currently have at least some gender biases that they will pass down to their kids.

Why specify "white"? Your statement is probably true, but there appears to be an implication that it doesn't apply to the non-white population. That has not been my experience (if you construe "white" to mean "as opposed to black/Asian/Hispanic/etc., my experience is by observation and word of mouth; "white" could also be interpreted as more like "WASP", in which case my contrary experience is also personal).

I more or less agree with what you said, especially this:

BUT, I am not a hypothetical, so you can interact with me and learn what my actual response would be.

and this

Emotions have consequences, but consequences can be POSITIVE too! :)

and I certainly support this

and I'll often make it clear I'm someone they can talk to in private or right now if they want to learn more about my perspective.

And in general I am a big fan of actually having conversations with people, and clarifying each other's viewpoints; not barging ahead and drawing strong conclusions and acting on them on the basis of the only evidence you've gotten so far, but trying to get more evidence, especially when it's easy to do so. So in that, I think, we are in agreement.

I have a minor quibble which I'll address in another reply, but for now I'd like to say that I am not a big fan of the "bias spreader" vs. "cool person" dichotomy. I get the impression from your comment that you didn't, exactly, mean to suggest that everyone who has any sort of a gender bias is necessary a bad person... but that is an all-too-common meme these days; and I disagree with it.

Basically, if we allow that biases can be largely or even entirely unconscious, it seems slightly absurd to suggest that "bias spreader" and "cool person" don't overlap. Like, maybe the guy in the hypothetical didn't just pick a poor turn of phrase, maybe he actually has unconscious gender biases... but it doesn't follow that being offended is the reasonable response.

The question is this: is this a person who would, upon full consideration, prefer not to have biases and unjustified prejudices? Or is he ok with being biased? It seems to me that many more "bias spreaders" fall into the first category than the second. And taking offense does not seem like the optimal way to rectify the situation (that is, to fix this person's biases, which is what they themselves would want).

Then again, it seems that you, personally, react to taking offense in a calmer and more reasonable way than do many other people, which is great. I think (based on what you've said) what you refer to as "being offended" is a lot closer to my scenario #2 than it is to how most people react to "offensive" things, so again, I do not think we actually have a great deal of disagreement here.