I have been wondering this myself recently too. Well sort of. I look at the list of Witnesses and see that I don't know most of them or some of them are just not active. And sure my witness account 'Witness4All" doesn't post, I do (not as often as I like too now though).

So how many Witnesses are getting auto votes for doing nothing except keeping a 15W mini pc running? Because that is truly what a Witness Node is for Hive, I know because mine is 6 inches away from my keyboard right now.

So I do wish there was a better way to pick witnesses, maybe votes only last 2 months and you can only vote for a specific witness inside a post from that witness. It could be abused but it would at least make the witness account post every so often? I don't have a good answer haha