Specifically, I think these argument types are indicators of forum type mismatch:
- Support person in Action forum: "Don't be so harsh!"
- Support person in Discussion forum: "Your discussion of my problem is upsetting me."
- Action person in Discussion forum: "Why are you sitting around idly talking? You're part of the problem."
- Action person in Support forum: "Why don't you just do X?"
- Discussion person in Action forum: "Hold on, let's start right at the beginning."
- Discussion person in Support forum: "You're being irrational about this."
That last one probably made you cringe. It's the classic case of someone trying to start a conversation on the precise difference between "sexual assault" and "rape" on a forum for sexual assault survivors.
But the reverse, someone coming into a forum where people are discussing stuff and getting upset that they don't get it, is really unhelpful too. Why? Because we were all born knowing nothing, and we're all really stupidly wrong sometimes. You likely believed some really stupid things when you were younger, and said them out loud to your friends, having the kind of teenage philosophy discussions that meander wildly into the weird and cringeworthy. Some places on the net are just like that, and going in there and yelling at the teens isn't going to accomplish anything. It won't change their minds, it won't make you or them feel better, it will just be an argument.
The distinction between action and support is subtler, but I still think it's important. Action is about fixing problems, support is about coping with them. People in support forums don't need advice. They probably know perfectly well what they need to do, but most problems don't have quick fixes. And while they're trying to make things better, they need somewhere that helps them cope. Not all advice needs to be practical and maximally productive. In fact, if it's not actively harmful, let it be. Herbal remedies and exercises that do absolutely nothing but make you feel better? That's just fine on a support forum!
Finally, in a goal-oriented action forum, things are practical, which means trying to talk about theory is likely to come across as derailing. And in some cases, well, some advice can be pretty daunting. Coping with addiction, finances, weight loss and so on can involve some harsh truths.
Now that I've built up a nice symmetry I'd like to make clear that these scenarios are not equal. When it comes to problems and struggles, the people affected are much more invested than everyone else. The discussion-in-support case is being an utter asshole, while some other combinations merely rise to the level of frustrating and unproductive.
My practical suggestion, then, is to make it clear at the outset what kind of forum you're in. Not only does this reduce misunderstandings, it may also be a powerful weapon agains concern trolls and other such slime. If they start doing their thing, you can point at the sign at the top of the forum and say "I'm sorry, this isn't the right kind of forum for this." Which makes it much harder for them to try and act reasonable to gain sympathy from people not wise to their tricks, and may be less stressfully confrontational for you.
Finally, if you like this categorization, I very much encourage you to use it and link to it explicitly when setting up a new place for conversation. This can be a forum, a mailing list, a comments section. It can be a forum thread, as long as the discussion type doesn't obviously clash with the rest of the forum. "What can we practically do about global warming?" is probably fine in a forum about environmentalism, but "Is consent all that matters in rape?" is not in a survivor's forum.
But you cannot apply this categorization in mid-conversation. Even if it seems obvious to you that the conversation is of one particular type, insisting that everyone conform to your idea of what standard of interaction to use is exactly what this essay tries to prevent. Which means that if you get the itch to use this essay as a point in an argument, ask yourself - are you being awful to other people because of a mismatch in expected conversation type?