What you point to is the lack of record-keeping in a gift-based economy. That in turn makes it easier to freeload, especially when the population is large enough that you don't recognize everyone and thus don't know what someone's reputation is.
I may well be more inclined to spend time on a bug fix from a kernel developer, but I know only 2 kernel developers by name (Linus Torvalds and Alan Cox) out of the several thousand that have worked on the kernel. But at the same time, most kernel developers these days are paid to work on the kernel by their employers. They've already been compensated for their work to improve the commons. Volunteer coders haven't.
Given the venue I'm sure someone is going to jump in and yell "blockchain" here. :-) Who knows, maybe. I don't believe it's a silver bullet but it could be useful in some form.
It is certainly nice and benevolent to accept bug fixes that are offered on a silver platter; I would hope most if not all Open Source developers do so most of the time. However, that is different from it being an obligation.
Forming a gift-economy is hard enough. Creating it inside a money-based economy is even harder, because the good karma of gift giving may feel nice but, as the saying goes, "that and a fair card will get you on the subway." I can't buy groceries with good karma.
Until we have some clear, concrete way to convert good karma into groceries I stand by my statement that the status quo is abusive. And yes, that is that bad.
If the whole system collapses if we remove volunteer abuse, then the whole system deserves to collapse.