It would be nice to have some actual close reasons under the "off-topic" flag thingy.
One that comes to my mind is one posting to upvote questions, or to follow a proposal. We don't need that stuff cluttering this site. It could read like this
Questions asking to increase support for a proposal are off topic at the discussion zone. Instead of posting it here, try gaining support through social media networks
Another one could be related to starting a proposal. These questions don't show up often, but I am sure they have happened before. It could have instructions on how to start a new site, so then it is answering their question at the same time
Questions relating to starting a proposal do not fit on this site. If you want to start a proposal, select a category on the left of the main site, scroll to the bottom, and click "Propose a new site"
Questions relating to starting a proposal do not fit on this site. Area 51's main site is the place to do this. See this answer for more details