Why not downvote those posts yourself if you disagree with cover songs being rewarded? or downvote fan arts that are rewarded because they take in copy righted material and the artist creates their own version from an existing intellectual property?

No one can stop anyone from sharing content but anyone has free reign to upvote or downvote content. Isn't downvote also an expression of one's freedom to protest as one can also have the freedom to support with an upvote?