But yes, ideally the witnesses should decide so. Not sure who does the governance on Hive tribes. I guess it depends on the tribe.
Indeed probably the tribe owners. But those tribe owners do need to have also an interest in Hive, because that is their bloodline.
And not to mention that I forgot an important role. The advertiser.
The advertiser does curate and then reb-blog the post. This way the post does get more visibility and potentially some more upvotes. Due to the fact that he voted earlier he will get a share of the votes coming after him. But the article was already long enough.