Doesn't need to be a binary choice (above/below threshold) - it can be a spectrum -- also known as progressive taxation.
Would this prevent people from working hard and being enterpreneurial? Not sure but I think not -- for 2 reasons:
(i) success at that level requires more than just desire for money, because it requires pushing hard when the going is tough, and unless you care about it you will give up. we have heard this before from others (Steve Jobs?)
(ii) a successfull entrepreneur will still make more money than an employee, so the financial incentive is still there, even with greater taxation.
Would this prevent people from working hard and being enterpreneurial? Not sure but I think not -- for 2 reasons: (i) success at that level requires more than just desire for money, because it requires pushing hard when the going is tough, and unless you care about it you will give up. we have heard this before from others (Steve Jobs?) (ii) a successfull entrepreneur will still make more money than an employee, so the financial incentive is still there, even with greater taxation.