It's very possible that the unspoken culture at Amazon is work hard above all else. If you've read "The Everything Store", there is a quote, something like, (regarding Bezos) "If you're bad, Jeff will run you out of the company. If you're good, he'll ride you into the ground." It also talks about Jeff firing an early and long-time employee, he did throw a party for him in Hawaii, because Amazon no longer had a use for him. I don't know if either are true, but if true, I could see that attitude creating an unspoken culture of, "I don't care about your problems, we have work to do. If you can't do it, we need someone who can." I can also see how the success and the stock price, given the commitment to work above all, reinforces that mentality.