I've never signed an employment contract under duress. But this is exactly why I suggest to people to always be searching for another job, which means the next contract you sign absolutely does not need to be made under duress. Every job ive left I've had something lined up.

But that being said, even if what you say is true, that doesn't mean any arbitrary thing you think should have been included actually should have been included. So trying to paint increased profits for the owner as theft because still doesn't hold water. Sure you should have gotten more, but was that it? Probably not because plenty of people take these jobs not under duress with no profit sharing.