I think people should keep a few things in mind.
First, we have only one side of the story. The claim is the advisor never spoke to her about the problems he had with her, and we shouldn't simply assume the claim is true. OTOH, I can easily believe it is, given my experience in grad school. While some professors were quite fussy about quality in the thesis, others accepted that most PhD's (in engineering) are not targeting scientific research after the degree, and lower the standards to allow them to graduate. But they absolutely will not support such people in getting a research position at a university or a government lab. Some are open about it: "If you're targeting research and want my recommendations for that endeavor, this is what you need to do. If not, then all you need is X, Y and Z." Unfortunately, not all advisors are as frank.
Also keep in mind that the person may well have been a very competent researcher, while simultaneously being hard to work with. It's quite fair to point it out when asked, and it's quite fair to disrecommend someone because of it.
I don't think the article presents any evidence of active blacklisting, where one is going out of their way to tell everyone (without solicitation) "Don't hire this person!"
Finally, the real issue: What role should references play in the hiring process? I personally would love a world where we never rely on letters of recommendation and references - I think they are the weakest link in the hiring process. However, if we do accept references/letters of recommendation, then everything in the article is fair game. If you ever asked someone what they thought of a candidate before hiring them, you are part of the same culture that this person's advisor is.