There are already sites here that are subcategories of other sites. Poker and Chess exist despite being part of Board & Card Games for example.
However, it's not the job of Arqade as a site to make this happen. It'd require members from the Minecraft community here to start the site.
Please wait 5–15 seconds for the images on this post to load. I'm afraid I can't upload them to SE Imgur because the files are .svg.
I feel like I am in an appropriate position to answer this question based on my previous experiences, including one very similar to the issue that is going on now.
For those of you who haven't read my profile page yet, I am an ...