Silver gain in the game is easier than ever. Its not worth it to buy the pearl items to sell on the MP. This is why you have seen a decrease on overall pearl item sales. Plus a lot of the hard core whales are probably hitting their gear goals so dont need to swipe as hard nowadays to advance. Plus there is the fact that if they are buying pearl items they could just be using them themselves (hi costume heating looking at you). So the only real way for them to fix this is to increase the silver gains from pearl items. But they also know that it will probably cause another huge outcry from people about more P2W and will possibly see another wave of people quitting over it.