I think a lot of what this says is accurate, but I think it downplays something important. It's not just that there's a lot of money in Wall Street, it's that it's not a great time to be (for example) a physicist in this country, or at least it wasn't when I graduated. I remember a friend of mine telling me how you were typically looking at two postdocs after your PhD, and then your options were either to be an academic or to build weapons. (That guy, ironically, is the one who stuck with physics.)
So apparently a lot of people took the money. Those kids could grind, and it all must have just seemed too easy. I find it hard to judge too harshly. A part of me feels like we failed them as a society, in the way we collectively assign value to human activities. Because their minds are capable of things I can only imagine, but we couldn't think of anything better for them to do than this.