it's easy to maintain these hours when you love your job and you believe in your company (and have great teammates). you can't let equity and/or salary be your sole motivation; you have to actually enjoy what you do.
Sorry, but I don't regard anyone who puts in these kinds of hours for a salary and chance at a token bonus (say 40% of yearly base) as rational. You've only got so many productive hours in your life. If you love working so much then take a second job you love and work both at reasonable hours. If you ever wake up and realize life isn't all about making other people rich, at least you'll have a lot more to show for your effort.