Our economy is based upon mutually beneficial relationships. Relationships based upon strengths, weaknesses, knowledge, ability and comparative advantage. Relationships that are not mutually beneficial are not maintainable and people who exploit this fact are assholes.
Pushing people to the limits and beyond can be mutually beneficial. This may open new horizons for those involved, but setting goals at unachievable levels without consensus burns people out. It damages their lives in innumerable ways and reduces their overall productivity. In short, it is not mutually beneficial. This behavior is the reason that many workers formed trade unions to oppose exploitation in centuries past.
We often hear about Microsoft Millionaires and Bill Gates is no choirboy. However, with the revelations that Steve Jobs was an exploitative asshole, it comes to mind that there is no such thing as an Apple Millionaire. There are people who made money on the stock, but I have not found one story of an Apple employee becoming vastly wealthy beyond Steve Jobs and Steve Wozniak and the forementioned article may explain why:
...nobody every got rich by working for an asshole.