Yes. This is precisely what I would have thought advocates needed to be researching, and I'm amazed there's so far just been defensiveness, circling of the wagons and ad hominem dismissal of the claims ("it's just motivated cognition", "she has no plans to sign up"). Which are natural human reactions, but that doesn't make them good ideas.
Is this reaction evidence against cryonics?
Again, why does it have to be evidence against cryonics instead of, say, Alcor or SA or CI? She's not discussing the theoretical desirability or practicality of cryonics.
I recently found something that may be of concern to some of the readers here.
On her blog, Melody Maxim, former employee of Suspended Animation, provider of "standby services" for Cryonics Institute customers, describes several examples of gross incompetence in providing those services. Specifically, spending large amounts of money on designing and manufacturing novel perfusion equipment when cheaper, more effective devices that could be adapted to serve their purposes already existed, hiring laymen to perform difficult medical procedures who then botched them, and even finding themselves unable to get their equipment loaded onto a plane because it exceeded the weight limit.
An excerpt from one of her posts, "Why I Believe Cryonics Should Be Regulated":