The integrity of the game falls apart when you can't see the votes. People need to be able to verify that votes are real or sus or else it stops feeling fair.
The entire point of gameification is that people don't feel the game is rigged. Democratisation of posting needs to be verifiable to end users or else they'll just slowly gravitate to platforms they feel like they trust more.
It's literally why we ditched the Down vote here on Hexbear. Because bots were down voting everything regardless of content and only up voting the things the bot was programmed to upvote. As such it became impossible to know what real users thought about stuff. By making it upvote only, we thoroughly decreased the amount of rigging outsiders can do to our Hexbear system™.