Even when I did a startup, I held pretty normal hours. Working on someone else's problem to make them rich is silly to me. I think it's something that you either get or you don't. I don't plan to convince you to change sides, but I'd 100% of the time rather spend hours 8 or 9 through 12 working on my own hard problems. They're easy to create. I definitely had more responsibility, did more coding, and felt more energy at a startup than a big corp though. Pay and nearly everything else was shit in comparison.
If someone did 10-12 hour regularly on my current team, we'd be pissed. It would set a new normal and management would think they could start replacing people until they get 10 of those guys that are willing to sit here half the day.