There is absolutely nothing wrong with seeking people who voluntarily wish to work those hours.
It is in fact much better than implicitly expecting long working hours like many jobs while not being upfront about it - that can trap people into a deal they did not fully understand. This is the opposite.
It may be unsustainable for the vast majority of people (me included) - so what? I don't go around crying about coal miners jobs because it would be unsustainable for my physical frame, I just choose not to apply.