However usually those company's prefer the greener type of employee who is willing to take this kind of abuse. Get a Salaried position and they whip and beat you to get the work out of you.
President, CTO's can generally spend a lot of time working in order to keep everything going.
40 hour work week is the LAW in the US FYI; if they are asking you to work 65 hours a week and you are salaried. You are entitled to overtime pay.
Employers love it when employee's don't know the law; it allows them to get away with not paying them overtime when they are legally entitled.