(But for what it's worth, this doesn't seem to me like a cut and dry description of what happened here; sales is a very cut-throat quota sensitive profession in my experience.)
But nevertheless, I empathize with people who also have to figure out how to put food on their own family's table, in a profession (HR) that is itself very sensitive to downturns.
The comments in this thread read to me like software developers who have not faced a world where it is not easy get a better new job easily after quitting one that sucks, and / or who are young and unattached with very few expenses, and struggle to put themselves in the shoes of someone for whom a principled resignation could have devastating consequences.
It just seems to me like a classic case of shooting the messenger.
In this case, it's not clear that this isn't the reason. That's something the laidoff employee calls out herself; the HR people aren't familiar with her KPIs or work. They don't have any expertise in her industry, and it's unreasonable to expect that.
If my employer tells me to call a person and tell them they are fired because they did a bad job, but it's clear that this is not the reason, I would say: sorry, but I'm not going to do that. Remember, it's an "employer", not a "boss".