Less sharks = noobs lose money slower = play longer. Noobs' relative skill level also goes up, which has a ripple effect of word-of-mouth advertising. Plus, Party knows that sharks are gonna play there anyway, why make accomodations that cost them money? It's true that Party employees are morons, but their business sense is almost so stupid it comes full circle to genius. They are really toeing the line where they make the most money without alienating old players. Party killing rakeback doesn't seem good to YOU, but it is fantastic for them.