Source: am a millennial and experienced the huge pressure to go to college, especially an expensive one.
Not only did my family perpetuate this idea, but my middle class suburban high school did as well. Our guidance counselors actively were involved with the local state universities. They spent a lot of time shoving the idea of attending college down your throat. Maybe they only did this with the higher performing students. I even was going on college tours in 10th grade, through programs at my high school. At the time, I really didn't think there was another option aside from college after high school.
Then the law was changed as well so only student debt was not dischargeable in bankruptcy while every other type of debt is.
It's disengenous to imply that these were freely made choices. Well running capitalism relies on information parity between both sides and not interactions where it's all of society and a massive industry trying to convince undeveloped minds to make bad choices