You will care when they're the only player in town and can raise the prices as much as they want, it's economics 101. Right now we shop there because we want to, but then we'll shop there because it's the only place left.
With that said if people don't like working for Amazon then why do they? Quit. While it is scary at how they can get in and destroy any market, they really do deliver the best service and prices. I've been shopping at Amazon since the early 00's.
Amazon's story is awesome, Bezos actually invested money during the .com crash and he originally mentioned how he was in the market of books and now he is quoted as saying that he is in the market of providing what costumers need"