I somehow understand your point, but I think the spenders will still be spending to get those rare ninjas faster and get the advantage over only F2P players (the mtaching doesn't need to be exact precise, just more player friendly, not hitting you with a player 3-4 times your power right away). But in the long term I think casual spenders who recharge every couple of months would stay in the game longer and would also have the desire to spend more often to get that rare ninja that would make them become even more competitive when being matched with players with similar BP and that rare ninja would be the difference in beating them even if they lack in power a little. But I know Oasis does not care about their players/community being loyal and happy with the game, they just care about the money and that is why I believe they don't do anything about the level freezers and matching system.