Your poll is a little low. Most kids in my age range would consider $40,000 to be on the low end. I know a bunch of guys with $100k+ in loans.
With $50K and more as the highest category, it shows my age. I should have put the categories into 10K increments instead of 5K increments.
I was class of '82 and was first who had to pay for school in my state system. People who graduated high school in 1981 enjoyed a free state college year through that whole year, and all years before that was free. Some point before the 1980s, textbooks were thrown in and state college was as cheap as high school. Unless you chose to live off campus, college was virtually free other than clothes, entertainment, and school supplies like notebooks, typing paper, pencils, pens, calculator, backpack.
I took my time at school since it was cheap and lived a musician's life, too. But I took sooo long to finish that by that time school, even state schools, were expensive. I was so used to "free and cheap" that I only started to get into debt in grad school and the thought of debt, especially with a fairly useless grad degree, was unthinkable. Had I went that 6th and final year, I would have amassed twenty grand in debt counting relocating to SF and getting settled in. To me that was way past my comfort zone since I had a positive net worth and didn't want to fall into a hole and still be in debt into my mid-30s.
That being said my former employer paid for school with a credit card, being a foreign student, and did all 6 years and got his BS and MBA but had $25K but with credit card level interest. He worked his butt off while in school and would have had three times that in debt so he did well. He did an additional 2 years in computer networking school and was nearly 40 with no house, a wife back home in another country, and $25K in debt. He didn't complain and from his perspective it was worth it to get an American or British education at any cost and that level of debt, equivalent to two years in his country with a high level job, was totally worth it. If he was lucky, he would be out from under it all by age 50 but two American degrees in his country has as much prestige as having an MD from Harvard in the USA. If there are Americans willing to go $100K in debt but have that Harvard piece of paper, I guess having a 1/4 or that in debt with a piece of paper seen as "Harvard-like" in his country is not that crazy. That $25K would take as much work paying off there as $100K over here.