People get stuck in bubbles. In the academia bubble, the only people making a living are professors and to become a professor you need a Ph.D. So they are the example people follow. They don't realize that becoming, say, an accountant might be a better move because there aren't any accountants in the academia bubble.
People who get into PhD programs should have the general intelligence to realize that every PhD candidate can not become a professor. It doesn't add up in any hierarchical organization like that.
If you understood how people actually think, in a cognitive-science sense, you would understand why "X should have the general intelligence to realize Y" is a complete load in almost all cases.
I'm sorry. Clearly some of the self-appointed smart people of HN were offended by my naive remark, uninformed by any research in cognitive science or other relevant discipline.
