I'm sorry, but "being queued up on disk IO" and "burning up XX watts for no good reason" are not related at all. For decades we have systems which do not do busy loops on external store access. They go into low power state if they really have nothing else to do in that time. They also use crazy "new" things like interrupts, notifications and wait queues. This article actually explains how mongodb does not wait for IO, but handles other requests in the meantime. (within the current known limitations of writer/writer locks, etc. of course - i'm not saying it's all perfect)

Did you really read the post before arguing this?