Downvote if you like - it's simple mathematics. Money (especially government-subsidized money) is damn near free today. Rushing to pay it back at near-zero rates is foolish.
Don't know why people are downvoting you, what you say is very sensible and financially completely right - if the interest rate of the loan is below what you can get in interest on a nearly risk-free investment, then it is cheaper to pay the loan as slowly as possible. Having said that, I disagree with you that it is foolish to pay back loans as quickly as possible. Having no debt makes it much easier to live with no income (without having to declare bankruptcy). If that isn't something you aspire to then it doesn't matter, but I would personally enjoy that very much and will continue paying very close to the absolute maximum I can afford each month on my admittedly cheap loans.
I came to the same conclusion when I consolodated into a 30 year loan. Since my loan doesn't grow much faster than inflation (if any), I won't save much by paying it early, and the monthly payment will seem smaller every year.