Haven't looked more closely at the numbers here, but there are only 50 * 6 = 300 BTC created per hour. If each of these is averaging 24 BTC per hour, then that

Haven't looked more closely at the numbers here, but there are only 50 * 6 = 300 BTC created per hour. If each of these is averaging 24 BTC per hour, then that's practically 8% of the total computing power in the bitcoin network. That would mean that 13 of these would have more power than the entire network. Even if this were the case, the gains from such a scheme would be short-lived, though, as the difficulty adjusted to compensate. Then you're competing with everyone else who has bought these, and fighting over the marginal cost of electricity vs. the upcoming reduction in the reward.