This doesn't address the storage requirement problem. 15M transactions per day * 250 bytes per transaction = 1.369 TB per year. After a year most home users wouldn't be able to run a full node without shelling out for extra hardware. After 10 years you'll need to spend hundreds on hard drives just to get started. Sure, it's still decentralized in the sense that you can still run a node, but it'd be closer to usenet (users connecting to independent server farms) than what we have now.