I think there is also a lack of social awareness. Resources like USENET groups sci.math got trashed because people took inappropriate advantage of them, some under the guise of "free speech". They have become (and may still be) festering cesspools of spam, primarily through lack of moderation. The tolerance you speak of would similarly ruin the resource that is MathOverflow. If you want debate and discussion, find a place that is suitable for it. MathOverflow is not such a place.

Put another way, the number of "relevant mathematicians" is likely to be very small. You may need to do more than make MathOverflow posts to find one of them.

Let me remind you of meta.mathoverflow.net/questions/1717 . Don't give up trying to make the problem more attractive. Also, accept that most of the MathOverflow community won't be affected by your attempts. As long as you meet community standards though, you needn't care about it. You need to find the one or two members who are interested. Keep looking, thinking, researching, and tweaking. Good luck ro you.

Probably academia.stackexchange.com, as many of the relevant issues in your question are not specific to mathematics. Also, the question is a little broad and does not admit of a concise objective answer. It's a good question, but not quite within the mandate of MathOverflow. (Yes, we are still trying to figure out what that mandate is.)

Indeed. However, the first two are slightly discouraged as sometimes being too broad. Also, the first two usually involve less work to answer because someone reading it either has an informed opinion to share or saw a web page on it. Answering the last question involves more work, and usually one has to wait a few years after publication to find someone who can answer it reliably. I believe a major criticism of the MO question on Mochizuki and ABC was " too soon to ask" .