That's not the point. Too much power is in one pool. What if some sort of government agency takes control of his pool? Currencies are all about confidence. No confidence, no currency.

Miner greed puts the network at risk because people want to see many tiny payments rather than wait for larger ones and pay 3% for the privilege.

Do miners really want to take the risk so they can see 0.01 or 0.02 BTC a block?  Or wait a little longer for 0.07 a block? You know what I mean.