Meanwhile, Steve in the next cube over is answering the call as he's next in line, he responds to the email that comes in and generally puts forth more effort than you. This is recognized by management. Steve gets a promotion eventually, you do not. Moreover, management sees Steve's fervor, they want more Steves and they hire more Steves. Eventually there is a dip in funds and we have increased costs, someone must go. Who do you think they fire? (Hint: it isn't one of the Steve clones).
I'm not trying to justify it, but the reality is whoever makes more money for the boss, whether the lower employees make more is irrelevant.