I would be putting words in someone's mouth if I wrote, "You said X..." when they did not say X, but rather something that I think (rightly or wrongly) implies X.

What I did is something different, but I agree that it's not obvious how this is conducive to productive and useful conversation. I know, it looks like I'm just trying to "score points." So, let me explain myself.

This kind of dialogue actually is productive and useful.

People reading my comment who were taken by a logical fallacy (including the person who wrote it) get to see that and learn something.

The person who wrote my comment (me) gets to practice writing clearly and concisely, and will get instant feedback if there was a failure or mistake. (Either in exposition or logic - and I readily admit I make logical mistakes all the time.)

As further evidence that what I said is useful, I submit that I have a double digit number of upvotes.

I wish there had been a way to indicate I wasn't just being snarky/trying to score points, but it's hard to convey that online, short of saying "BTW, I'm not just being snarky here, I actually think this is important." Maybe I should have done that. I'm open to suggestions here.

You could have conveyed the non-snark by just omitting your parenthetical. Everything before that is totally valid, but the parenthetical invites the kind of reply that doesn't actually move the conversation in the way I think you intended.

(Edit, adding): Also, when you use "", it's much better if you are actually quoting. If not, you are putting words in their mouth.

Thanks. This is useful. It got me thinking.

If I had just not put the parenthetical, it would make it look like I was "really asking" the question. That would treat the derivation in question as potentially legitimate (it's really not), and also invite serious but non-useful responses.

So that leads me to conclude that I just shouldn't have phrased my point as a question in the first place. I could have just stated my point as a statement, not a question.

That's pretty much what I was trying to say with, "What is the point of even asking a question that you're sure you already know the answer to?"

I guess you were trying for a rhetorical question, but I think that requires either:

1. The answer to be obvious to everybody, both asker and audience. E.g. "Do we really want to destroy all life?"

2. The question to be a lead-in to a discussion or argument. E.g. "Is it better to have more blue cars available for consumers to buy? I think so, and here's why."

You didn't do #2, so it looked like #1, but in context that's horribly dismissive.

I'm tired of people misusing the concept of a strawman (or other equivalent concepts). Just because someone pointed out something weird or bad about an argument doesn't make it a strawman.

The OP comment was not misrepresented. He started from "black people historically lived in greater proportion where soil was good for cotton." He ended with "affirmative action is still needed". Yes, the OP said more than that, but those statements as given are correct.

I don't know where you're getting any of this. My objection was to asking the question and then assuming that it could not be answered before even giving the other guy a chance to respond.

That wasn't what he said, and the comment itself was a response to such an attempt, but whatever.

That wasn't what he said? How do you figure? He asked a question of the other guy, then answered it rather abruptly in the next sentence.