We're talking about the ones that get in the way of what you are doing... "Just avoid them" is what I'm already doing as much as possible, lol? This game rewards you for pretty much everything else except killing normal skels.
"Why do gamers need to be rewarded for game activities?" I don't know how to answer that question... It should be clear to anybody: in-game rewards are the only reason we play the game...
A better question is "Why wouldn't the Order of Souls WANT to reward a pirate for killing more skeletons?"
We already have a chance to find random skulls just lying on the beach in the game world. Not sure we need another way to get random skulls in my opinion