Why don't we start a sub forum that is specifically for questions relating to magento extensions? Instead of closing questions on the main forum, etc.
We don't start a subforum because we cannot. We are not in charge of creating websites on SE. And I doubt someone will agree in making such a sub-website because there will be a waste of time. here will be a lot of unanswered questions.
And extension developers should offer support for their work. If they don't offer support by email I doubt they will offer support on a SE website.
As for the closed questions about third party modules and you think you can answer one, just vote to reopen or flag it for moderator attention saying you have an answer and they will be reopened.