KKH's article was not wise, grad students have every right to say that ticked them off, yes, this is true. But also the idea that this is somehow dangerous for her is ridiculous. Nobody cares what grad students think. They _always_ complain, everywhere, they're gone after a few years, and faculty often kind of tune them out.
Also, although I didn't like her column, she wasn't wrong about the "not hacking it in academia" part. Or the cannibalistic world of the academic job market. Or that everyone else is making their dissertations good so you better too. All of that was right. The grad students' letter was a nice sentiment but not something that helps grad students make decisions about their lives.
The biggest problem with KKH's column was it was too optimistic.