No, I get what you're saying, but perhaps I should explain myself further.
A bit of context:
In the UK, Conservative Prime Minister Margaret Thatcher froze student grants sometime around 1990. After that, they began to be reduced (under Conservative Prime Minister John Major's leadership), so by the time I was at university (between 1993 and 1996) I was only given a small grant. This is because my parents were considered too affluent. They were sending my three siblings to private schools, so the money they could otherwise have spent on funding my university was spent there instead. That meant I had to make up the rest of the money working part-time jobs. I had no issue with this. Good life experience. I also took out a small student loan (small in relative terms, as you'll see): £3000, to help cover the cost of the student films I was making, and to help pay for trips to international film festivals in places like Amsterdam and Paris. The latter were luxuries in the scheme of things (though also of educational value) but for the films, I had no alternative. Again, I didn't view this is a hardship per se. Post university, I landed a job that paid enough so I could pay back the loan, which I finished paying over twenty years ago.
Subsequently, Labour Prime Minister Tony Blair wanted to get more people through university, but of course, that meant a funding problem. His solution was to make students pay prohibitively expensive course fees, abolish grants entirely, and to make student loans the default for anyone who wasn't mega-rich. This irritated a lot of voters as you can imagine, so his pledge (and the pledge of subsequent governments) was that students wouldn't have to pay back loans until they were earning a certain amount, and eventually, after a certain number of years, the debts would be written off. This more or less appeased the public (though not me, as I still consider it lunacy to try and get everyone through university, as it devalues the degree and not every employment path requires a degree).
My suspicion (though in all fairness, I have not followed the debate accurately in the US) is that those in favour of debt cancellation on your side of the pond are looking to introduce something akin to the UK model. I think that is fair and reasonable. After all, this isn't the same as taking a regular bank loan (in which case, I would agree with you - be a grown-up and pay it back). This is about a young person being saddled with an average of about £25,000 of debt at the age of eighteen. Unless you are mega-rich, that is deeply unfair, and I don't see why the brightest students should be stymied in their pursuit of higher education - which will ultimately benefit all society - because the majority of them aren't massively rich, and they are unable to take on such huge debts at such a young age.
Therefore, offering student loans under the terms and conditions the UK government currently offers is, to my mind, the least they can do in the name of basic human decency and compassion. If you're telling me the US is a lot more hard-nosed than that, and can't see the nuances of this situation in comparison with, say, a regular bank loan, then shame on the US voters and on US politicians for their hard-heartedness and their myopic ideas about education only being for the super-rich.
At the very least, there ought to be measures in place where US graduates only have to pay back their loans once they are earning a liveable salary. My understanding (anecdotally, from young people I've spoken to in the US) is the repayment attitude is far more brutal, ie you start paying back after university regardless of employment circumstances. This to my mind is stupid and cruel. Then again, I consider a lot of US social political ideology stupid and cruel (the lack of state funded medical care, for instance - the National Health Service in the UK may be far from perfect, but at least people aren't faced with ruinous bills running into the thousands if they get ill, whilst medical insurance CEOs profit from the misery of millions).
So yes, US taxpayers can remain stubbornly against a more nuanced view on student loans if they wish. That is their prerogative, as you say. But personally, I don't think it is fair to have the same attitude to student loans as with bank loans (or other kinds of loans). I favour what we have in the UK instead, as a bare minimum.