I was sarcastic, but you were sarcastic first. At least my comment had ideas within it, yours was a contradiction that didn't supply any helpful information to anyone. It was just mean.

I think you're overreacting to common_law's choice of language. OP will speak for themself if they felt offended or domineered, I'm sure.

The reason to avoid arguing with hostile arguers is not that it is impossible to learn anything from such people (although the expected information value is likely to be low). It is because doing so is dangerous or costly on a psychological, physical or economic level.

I disagree with you about expected information value. Intelligent people are often irrational, I'd even say the majority of intelligent people are irrational. There are plenty of dumb irrational people as well, but it'd be quite uncharitable to assume that arguments with them are what's being defended.

I also disagree that arguments with irrational people are dangerous, psychologically or physically costly, or economically expensive. Why do you think that this is true?

I think that even arguments had in person don't typically end in violence, and that arguments online practically never do.

I don't see how arguments generally cost anyone money either, except in the same opportunity cost sense that anything does - but people aren't optimal utilitarians, so this is a pretty lame criticism.

I agree that arguing with irrational people can be psychologically unhealthy, but don't see any reason to think that's the case in the majority of situations.

There are imaginable arguments with irrational people that would end in violence, loss of money, or loss of sanity, sure. But obviously those aren't common consequences.

Of course if you enjoy arguing with hostile people or think it is potentially useful practice then go ahead. In much the same way if you think getting into physical fights will teach you self defence skills then go ahead and insult drunk guys at the bar till they take a swing at you.

Nobody here is advocating intentionally getting embroiled in all imaginable possible arguments, that would indeed be a terrible idea. It's assumed that discrimination is still applied when deciding whether or not to enter a conversation. Your analogy is very biased because it overlooks this. Your above arguments have the same flaw. You've evaluating common_law's idea by pretending the idea would be implemented by someone without any judgement whatsoever, which is unfair.