I agree with Karen Tiede’s answer: the most effective way to counter a bad answer is with a good (and dispassionate) answer.
The most *easy* way to do so (and indeed, the one I usually use) is to comment. But not everyone wants or accepts comments. And if you’re worried about sounding offensive, you’re unlikely to want to engage in comments to begin with.
I disagree with Karen’s premiss as a way of participating in society, as opposed to Quora (“It’s not my job to consider other points of view”), because being open to considering other points of view is the responsibility of a citizen. Even as an approach to Quora (“this is not a debating site”), I am uncomfortable with it: it truly comes across as the stuff of echo-chambers.
And yet, in my own practice on Quora with answers (as opposed to comments), I do the same thing. I’m often not interested in rewording questions, if they’ve been found to be wanting in someone’s comments—even if I agree with that comment. I will edit to add things I’ve left out, sometimes, particularly in matters of fact. But edits of answers don’t trigger renotifications to everyone who has already answered your question. Just as comments refuting you are nowhere near as visible as new answers refuting you.
And I’d rather let my answer stand, as the best record of what I thought—if the answer is a matter of opinion or judgement rather than fact. If the answer is debatable, well, let’s have the debate in comments, *I*’m fine with that. But my answer stands, and the best way to refute it is a counter-answer.
I’ve often encouraged people to post a counter-answer; they rarely do…