I like this, but I think that upvotes correspond to things people enjoy, which may or may not be of high quality. I.e., shitposting subs would probably be rated "high quality" when, like... it's literally the point to post shitty content.

Also, as stated, that means we have to sum over the entire time history of the community. We would probably want to limit the time history of what is summed over, subject to a maximum for subs with high post counts (like the shitposting subs.

IMO it's a great suggestion, but I think it needs to be part of a weighted combination of factors.