Why Do Small Businessowners Not Mind Working a Million Hours?

Economic profit.

Economic profit is a term in economics which is defined as total revenue less opportunity costs.

Opportunity cost is that which we could have been doing with our time or money had we not done this. I could have been eating lunch if I weren't posting to the blog, but since I would rather post to the blog I have overcome that opportunity cost.

When people work for themselves, they have a certain amount of money they need to make to overcome their opportunity cost (i.e. to overcome working for somebody else instead). If you really don't want to work for somebody else, or you're really happy where you are, the money doesn't matter because it doesn't take much of anything to overcome your opportunity cost and turn an economic profit.

The flipside of that is that if you hate your job or your situation, no amount of money will make you feel like you're "turning a profit." So control what you can- make your situation one you're happy with. Making more money might or might not be something you can control, and you can only hope it's never the deciding factor.