Epic Games*, Mihoyo**, IO Interactive, Bethesda/ZeniMax***, Deep Silver.
* Epic games is 40% owned by a publicly-traded company, Tencent.
** Mihoyo filed for an IPO in 2017, but withdrew its application for unknown reasons.
*** ZeniMax Media was recently acquired by Microsoft, and is now a Microsoft subsidiary. I’m not sure if this makes it count as a ‘non-public gaming company’ by your definition.
That’s literally the point of the downvote system. To downvote posts you don’t like, or you feel are out of place.
This seems to be the real issue you’re trying to fight. It seems like only permitting downvotes on communities that the user has been a part of for greater than 1/2/7/30/pick-a-number days would be the proper solution. If people in a community are downvoting a post, then it means they don’t think that post is worth sharing. No admin, moderator, community owner, etc. should be able to change that.
I am strongly against removing downvotes.