Here are a couple of paragraphs to ponder, written from the viewpoint of a new faculty member.
"From the first day of the first class, I saw students who had great expectations for their potential … careers but little awareness of the likely reality, even for graduates of a prestigious college who were headed for top [graduate] schools. I know now that my students were not alone in displaying this gap between expectations and reality; from talking to young [people], I realize that it contributes significantly to the personal crisis that many new [doctoral graduates] experience when they leave … school and try to get a job. …
"The picture isn't pretty: Students with false expectations, deans with an overwhelming incentive to tell students what they want to hear, and few people with any reason to offer an effective counternarrative. It's not surprising that there have been so many more … students than jobs, and so many unhappy [people]."
I’ve made a couple of changes to disguise the fact that Steven J. Harper of Northwestern University, in his very extremely illuminating essay  in The Chronicle of Higher Education, isn’t talking about science students and young Ph.D.s, but law students and young lawyers. The details of the two professions differ a bit. For example, government-backed student loans rather than government research grants encourage universities to recruit hopeful young law students for advanced education while paying no heed to the brutal employment scene that awaits them when they leave campus. Just substitute “science” for "law" and "scientists" for "lawyers" in the paragraphs above, and the description fits remarkably well.
Harper also uses a term, "pyramid model," often used to describe academic science , in which the labor and hopes of many low-level people support a system that benefits the interests of a favored few senior people. In reaction to this situation, law school enrollments have dropped precipitously, Harper reports, in a trend resembling the "internal brain drain"  of talented young Americans from science to other fields that has been identified by University of California, Davis, computer professor Norman Matloff. Because lawyers must be citizens, law schools can’t recruit students and postdocs from abroad to fill the gap, as science departments do. And because law students must pay tuition (in contrast to science graduate students, who typically have their tuition waived), the market's response is more rapid and pronounced.
From the standpoint of the disappointed young aspirants, however, the story looks dishearteningly similar. And both cases prove that, as George Borjas of Harvard University  has told Science Careers more than once, the laws of supply and demand that you learned in Economics 101 work regardless of the profession in question. Also similar is the failure of institutions with the power to improve the situation  to do anything  about it .
Probably the only comfort in all this for young scientists, and it is cold comfort indeed, is that their situation is not unique.