The problem with downvotes in LemmyNSFW was very specific to that instance and its sexual nature. It boils down to the typical user doing the following:
- people use downvotes to signal "I don't want to see this"
- most people want to see naked women, not naked men
- the instance is supposed to be inclusive towards people who want to see either
As a result, content geared towards gay+bi men, hetero+bi women, and plenty non-binary people was consistently downvoted - and it was discouraging genuine OC for those demographics.
It was totally a band-aid measure, mind you. But it kind of worked?
An actual solution for that issue would be to require people to tag their content, and allow posters to pick what they want to see based on those tags. But for that you'd need further improvement of the software.