Tell me, how does one make several hundred thousand gold without: entering combat once, setting sail, helping manage a ship, giving commands to others to manage a ship, digging up treasure, turning treasure in, or accepting any voyages without exploiting something?

Rhetorical question, what he did, was exploit the loot reward sharing aspect of the game to achieve rewards for things he did not participate in.

They don't care about our feelings, but they do care about their Active Daily Player count. By allowing this booster to claim the rewards, they are setring precedent saying that no action can be taken against crew members who join your games only to hang out on the island and reap the rewards you earn.