Having gone through a PhD program myself, this smacks of truth. In the PhD program I went through, it was predominantly populated by foreign students and Ameri

Having gone through a PhD program myself, this smacks of truth. In the PhD program I went through, it was predominantly populated by foreign students and Americans whose parents paid for their undergrad (like me). Unlike in the United States, foreign college graduates typically don't have a massive amount of debt to pay off. When you graduate college and owe $35-120k in student loans, deciding between "lets get a job with actual pay" versus "lets make essentially no money for another 4-8 years" is a very easy question to answer, and it doesn't favor going to grad school. If you're American, your options are (1) very cheap undergrad, which makes it more difficult to go to grad school, (2) large amounts of debt, which makes it infeasible to go to grad school, or (3) have had your undergrad paid for, which is inaccessible to most.