If your kids are in school and you work 10a-10p you will probably never see your kids.
I did the crazy startup schedule when my kids were that young too. I hope you're handling things with your partner better than I did. It sure seemed like things were going OK at the time! Heh.
I know some people with families who can do 10:30-22:00, but they usually have work-from-home arrangements during their evenings. The problem with investment banking ("eye-wanking") and other professional hazing cultures is they count working from home as time off. If you're not visibly suffering, it doesn't count.
Can you elaborate? I'm a family people; hopefully experienced and capable, but don't feel that I'm being biased against by the 10am-10pm work culture.
If anything, I find the typical late starting hours of twentysomethings (10:30 or 11:00) to be wonderful - I usually spend all morning with my kids.