People don't want unbounded discussion of ideas. They will debate a specific topic, like minimum wage, if you aren't allowed to talk about discussion and thinking methodology, how important the issue is relative to other issues, how it fits into the bigger picture of life, etc. And if you don't expect to actually reach a conclusion, and don't mind if they give up halfway through without explanation. The first time a problem comes up which isn't part of the limited topic (e.g. they think your communications indicate negative feelings, or they have negative feelings themselves), the discussion soon ends without problem solving because that kind of problem solving is out of bounds.
Most people and forums are hostile merely to continuing to discuss a topic for more than a few days. They're also broadly hostile to quoting what people say and replying to that, rather than everyone just making general comments on the issue and then everyone agreeing that everyone is smart and their comments merit respect. Also people don't like criticism – they don't want to be told what their mistakes are. People view mistakes as bad things to avoid because they don't expect to actually solve problems (if you can't/won't correct a mistake, being told about it isn't helpful).
People don't expect or seek progress. They think discussions are a hobby where you try to sound clever and entertain each other. They aren't actually trying to contribute to human knowledge.
I want to talk with people who are trying to make a substantial contribution to human knowledge. There are two ways they can approach that goal. They can think they already know enough to work on achieving it now, or they can think they don't know enough and be trying to learn enough to get there. Identifying which category they are in, or even saying what goals they do and don't have, is the kind of thing that people generally don't want to talk about (it's out of bounds since it isn't keeping the discussion limited to e.g. whether or not a border wall is a good idea).
Another question I ask people, which is also out of bounds, is whether they have a discussion forum or know of one they think is good and participate at. And if the answer is no, is that something they want and would they like to join my forum and actively participate? And if they are going to judge my forum negatively, will they say why and will that judgment be open to clarifications, questions, criticism, etc? People don't like to talk about this because it involves admitting they aren't looking for discussion. (Sometimes they pretend that they already have plenty of great discussion, so they don't need more. They have to claim it's private though, or else I'd ask to see it. People who claim to have lots of great private discussion, but none in public, are liars and also are, apparently, not interested in contributing their knowledge to the rest of the world.)
Lack of discussion means there are no paths forward for people's mistakes to get corrected, even when the correction is known.
Lack of debate means obscuring which ideas do and do not survive criticism. Which ideas can handle questions and scrutiny? Let's find out!