No i think they do get it, it's exactly like how subreddits work, if you don't like how /r/technology works, you can always create a new tech based subreddit moderated anyway you like. The issue isnt that there are multiple communities.
The problem, as always, is discoverability of all of these disjointed communities. I'm still new to Lemmy, but it seems like you have to rely on an external 3rd party tool like https://browse.feddit.de/ to find any of them. (please correct me if there is a better way I just haven't found yet!)
Unfortunately, I can't think of any way you could implement a voting feature for mods that wouldn't be abused. There are bots that would be inevitably able to vote in anyone they want
Also being a mod is difficult and you will have to make unpopular decisions. Sometimes the person you took action on will misrepresent what happened or outright lie to sway public opinion against you. People will take advantage of that to vote a mod out.
Do you have some way to prevent abuse like that happening?