There is such a thing for Lemmy, and Lemmy.ml has a “good reputation” listed on it.

See it here: https://gui.fediseer.com/instances/detail/lemmy.ml, noting the 15 “endorsements” (think upvotes) and only 2 “censures” (think downvotes), with another 2 “hesitations”. Fwiw, PieFed.social has 6 endorsements (all by Lemmy instances iirc) and 0 censures and 0 hesitations. lemmy.dbzer0.com has 49 endorsements, 136 censures, and 2 more hesitations.

So people definitely put censures and hesitations for some instances… just not lemmy.ml. Possibly the system admins are too afraid of being known by the very developers of the code that they are running on their machines to call it out? (I don’t have to remind you of all people that system admins in most countries cannot be anonymous - unlike the rest of us, most people in that situation have to register with their country to be responsible for the content shown, e.g. CSAM). Mainly around lemmy.ml there is simply… silence, by the vast majority of the Threadiverse.

Which matches every other policy surrounding Lemmy.ml around the Threadiverse: chiefly silence (at the “official” levels, e.g. sidebar text on an instance or in official documentation), leaving new people to have to constantly keep discovering what is going on regarding it, mainly on their own.