As others said it was a conscious decision of the developers, as it’s gamification of the system and they aren’t big fans of that.

I agree with this decision.

The Fluff Principle* makes easy-to-judge content get higher scores, and we do see it Lemmy. It isn’t a big deal because fluff ends on its own specific comms, but once you gamify the aggregation of score points, the picture changes - now you’re encouraging people to share content that they believe to score high over content that they believe to be contributive.

Additionally a publicly visible karma enables a bunch of poorly thought mod practices, like karma gating (“you need +500 karma to post here lol”) or automatically banning people with low karma (even if it might come from a single post/comment).

*“Hence what I call the Fluff Principle: on a user-voted news site, the links that are easiest to judge will take over unless you take specific measures to prevent it.” (Source)