what's the point of going to all the trouble required to wake up at 3 am, only to then waste your time by being tired and/or depressed?

There isn't one. But nevertheless, a large number of people spend a lot of time not sleeping enough and suffering for it. People are dumb. And it's partly because it's hard to mistrust your own judgement. Reasoning badly doesn't feel any different from reasoning well.

why do you assume that someone who has the intelligence, self control and dedication required to identify that waking up at 3 am is a requirement for success, makes a plan to make sure that he can deliver on that requirement and then follows through

Waking up at 3AM is not hard. You don't have to be in any way exceptionally smart or dedicated to do it - heck, everyone in the military manages it. As for "identifying it as a requirement for success", that's circular reasoning; you assume he's right, therefore he's smart, therefore he's right.