By default, Lemmy allows downvotes globally. However, when a server disables downvoting, it is similar to using a feature that is usually reserved for enterprises and very small, non-federated communities.
If a user prefer to not see downvotes, they can disable it by his favourite client settings, but the rest of the community should not miss this functionality for the pleasure of few users.
Bitcoins are an unlimited resource you can mine infinitely many of them. Both votes and bitcoins are raw resources that can be “mined” (earned) infinitely at a given rate by utilising the base resources time, compute, and internet.
U spend ur time compute internet and attention to earn votes that u spend on posts to affect the marketplace of ideas.