For point 2, you are right that education is a generally good investment. He're a scenario I would like you to think about though: A student takes out a loan so that they can earn a degree in a lucrative field that has a high demand for new employees. They use their loan money to embark on a 4-5 year process to get this degree, except just before they graduate, the economy changes and that field is no longer in demand. Now, they have a degree that isn't as marketable and are going to have a hard time paying off student loan debt and it isn't their fault because they didn't cause the economy change.

For point 4, you say that

Doing well enough in high school to get into schools that either meet financial need, or are good enough that employment isn't a problem afterwards, is extremely easy

It is not extremely easy. Not at all. I graduated 2nd in my high school class with a 3.998 GPA, graduated Summa Cum Laude from my undergrad program, and earned a Master's degree with a 4.0 GPA. It still took me a year and a half after graduating before I found employment in my field where I was actually earning real money. If I had needed to pay back loans, I wouldn't have been able to. (Fortunately, I paid my loans off with an inheritance, but I could have easily been in the other situation.)