Employees should not depend on the government for their ability to walk away from a job. They should depend on real assets that help them live more self sufficiently outside of their employment. This should include family, friend and other forms of community ties.
I think the point of H1B being tied to an employer is that a H1B entry needs to be temporary and not long term immigration. If you don't like your employer, or your employer is shafting you, then return back to your country and look for another job. If it happens to be another job in US with H1B visa, good for you. Start another temporary stint.