It strikes me as a "I did it, why don't the poors do it" type of argument when people talk about how they made it through college with low debt or debt-free and deride others who don't via a small sample size of people they've known in their lives with high college debt.
I have a Master's and only paid 38K (my B.A., I got debt-free). Did I use some of that cash to live? Yeah, but I was also working at the time teaching classes and tutoring - and if you're a teacher, you know that it takes significant prep time to do it right. It's not like I was like, "fuck it, I'll spend profligately." I needed the Master's to work in my career field.
Yeah, I got my B.A. for no debt, but not because I was smart. I was lucky to have people around me to show me opportunities. My parents let me know that they'd have no money for college, so I applied for scholarships, and I participated in a national competition through my high school that ended up awarding me money for scholarships only because of a teacher who recommended me for a spot on the team.
In other words, I was lucky to have good guidance because I was a dumbass seventeen-year-old kid who wasn't yet adept at making the greatest choices on a regular basis.
I was also lucky just to live in a state with low in-state tuition at the time. Tuition in general was so low, in fact, that kids from California found out-of-state tuition here to be cheaper than their in-state tuition to the Cal State schools, never mind the UC schools.
This country feeds a "need to go to college" narrative to people that specifically focuses on four-year major universities. College is half-necessity, half-rite-of-passage. Tuition is ever more expensive (and since instructors don't see commensurate raises in most places, you can guess where that money goes). I find it pretty unnecessary to shit on people who were told all their lives that they had to go to a good (read: not "community") college to get anywhere, thought that going to a good college would equal a good-paying job, and then got out to find that it wasn't true.
Were some of these people not great with their money? I'm sure some were. I know just as many people who worked through college (I did as an undergrad, as did pretty much everyone I knew). But I get why those people feel like they got sold some bullshit and are asking for loan forgiveness.
Frankly, I don't think that complete loan forgiveness for everyone is at all feasible, but we have a ton of shit to fix and a ton of places in this country that need help from people, and trading some partial or complete loan forgiveness for these former students' work and time seems like a start to addressing the specific problem of these voters.
I also don't give a shit if voters like Bernie's asking for loan forgiveness sounds like a caricature of what conservatives think that liberals really want from the government. Conservatives love their handouts more than everyone else in this country. Take away their farm subsidies or tell them that the major urban areas in their states don't want to send their tax money to the countryside to bus their kids from their remote-ass houses to school, and they'll bitch, moan, and whine about it more than any Bernie-or-buster does about his student loans. They can take the planks out of their eyes first when it comes to criticizing people for wanting government handouts.