Hey! You should totally create those communities by yourself, takes less than 5 seconds!! (Via the website though -- sadly the apps don't yet have that functionality...but will soon)

For example, I created beatles@sopuli.xyz, since there's no Beatles community here. Never modded any subreddit in my life, so it's a first for me.

I'm soon gonna make a list of maybe 8-10 communities I like and create them over here. Then I'll post links to them on the corresponding subreddits.

I don't plan to actually mod them actively, so I'll pass the modding powers to others if/when the communities get a good number of followers.

You could do the same, it's like being Johnny Appleseed!