The Karma system was never a great system, I thought. Due to group think on Reddit, at times people get downvoted for no good reason. I think it's good to have a little diversity and not just have a model. I like Lemmy so far a lot and I think it is getting better and better. This is exactly how red it should have been, but they ruined it, of course.
I would go one further and say that there shouldn't be downvotes. That way, "good" posts and comments still rise to the top, but you don't have somebody's comment sitting at -60 because they pissed off the hive.
But what's the actual problem with the ability for posts to have negative scores?
Are we trying to prevent people from feeling the unpleasant sensation associated with THE DISAPPROVAL OF OTHERS!?