At the outset as an entrepreneur there was a lot of calibrating and learning what was reasonable. We have a very sane and wonderfully paced life despite me founding and working on a startup for the past three years.
Entrepreneurs have a lot to prove - to investors, to the market, to customers. Time put in does not prove anything to anyone. Especially not your spouse.
Working reasonable hours (to me) is a sign of a healthy work environment, be it a startup or large corporation. Working under conditions of extreme uncertainty to offer a new product or service doesn't necessarily mean that all those hours together are going to be lost.
You must be really good at managing your time, being efficient, and resisting the urge to take your work to bed with you!
Do you offer coaching services? lol
If you make your business decisions right, there's no need to work particularly long hours.