My statement wasn't a value judgement on the choice to pay more per Ghps than a device is likely to earn, just that this seemed to be happening - and not just with Blade customers either. I'm certainly not saying that the decision to buy was stupid, just that the choice was apparently not motivated by profit.
Either that, or they have different assumptions about the likely future income of such a device than you or I or others do.
Although I agree with other sentiments -
if a device is deemed to be worth more to asicminer as a miner rather than as a sale unit, then we should mine with it. However that assumes we have the ability to deploy all our units - and given that that's not the case, as I understand it, selling them seems wise from a shareholder's perspective.
If ASICMiner only adds 100Ghps to the network over say the next 100 days and the network hashrate remains the same forever after, a Blade would take ~550 days to pay for itself, assuming constant uptime. So the Blade is worth far more as a sale unit than a mining unit, if people are willing to spend more than the device is likely to earn over a lifetime.