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.
It’s to encourage posting and comment by having a positive environment, especially on hobby community/instance. Lemmy is still small and post isn’t as many, and its full of people who is downvote happy and will downvote topic they don’t understand or care. Try build a community around that, i’m sure it won’t survive.
Let me flip it around:
If a user prefer to see downvotes, they can go to another instance that support that, the admin paying for the hosting shouldn’t need to listen to a few user.
It’s a setting, it’s a tool, let people building the community/instance adjust it how they want instead of dictating how they choose, isn’t that your point?
You can’t force people to be positive, they might still leave negative comments.
Lemmy is still small, so users don’t have the option to choose servers as they please. For instance, I’m looking for an instance where you don’t need an email to register (for privacy reasons) and where you can quickly create an account (I don’t have the patience to wait for days to get my account). Also, it should have a good number of federated servers working with it.
With these specific requirements, there are only a few servers available.
It’s pretty ironic that your posts are being downvoted here.