It's already about 1000000x higher than it needs to be. Keep in mind that all it does is prevent double-spends. There are other ways to avoid double-spends, to

It's already about 1000000x higher than it needs to be. Keep in mind that all it does is prevent double-spends. There are other ways to avoid double-spends, too, like taking the party to court. Mining does not need to be incentivizes nearly as much as it is right now for bitcoin to still function as p2p cash.