So I find your 'no minors allowed' rule strange, but I also know that's representative of the way the culture was when I was first in fandom to what it is now.
Like, when I joined fandom spaces and fanfiction, it was always 'tag your works appropriately, make the age rating clear (in the case of fanfiction), and if minors are still reading, that's their problem, maybe their parents'. But this was also a time when people didn't put ages on their profiles so you had no way of knowing how old the people reading your fics were.
Times have changed, so attitudes have also changed. MDNI didn't exist then, and now it's common on at least 18+ content, and some people are just not comfortable with minors on their pages, like you. I'm not saying minors should be reading adult content, but that doesn't mean us as authors are comfortable seeing it. Personally, I block blogs who interact with my 18+ fics if the age in their bio is under 18, but if they don't have an age, I don't bother because I imagine that they're my age and they grew up in the era of 'never put your age online, even if you're an adult'.
And quite honestly, I barely remember to put MDNI on my fics because I'm used to rating them on AO3 or FFN and letting the reader make their own choices.
I do wonder though – is there a reason you don't want minors on your blog at all, or if it just a preference (a valid one)? I know people have 18+ blogs and blogs that are safe for minors so it's easy to keep separate, so I was just wondering.
