As an aside I'd love to see the annual return for a company like the one you are describing ...
They also have a LOT they can right off the first year. With one time fees like PSU's, Electrical, Racks, Cooling, etc. They have quite the write off on taxes I would guess. And it is legitimate as it is a cost.
Second tax year I would expect right off's to be much smaller. I would agree though I would love to see a mining company this size profit. But it is going to be going up against some heavy hitters.