Cores have no effect on Max Power level. Your entire point is a fallacy. When a player Infuses they already have an Item that is the rank they want. You are basically saying players should have a tax for transferring Power level from a piece of gear they own to another piece of gear they own. In IRL terms its like owning a TV and told that if you want to hook up your TV to your Xbox/PS4 that you should have to pay a fee to Microsoft/Sony for the right to take your console from the TV in the living room to the TV in the bedroom. You might want to do that because, hey as PT Barnum said "A sucker is born everyday." but there are no justifications. No other game has a worthless mat and by your own argument, if Cores are so easy for you to get then why have them? If you like it as a tax system because you feel a value added tax is exciting then that is you.