As the gentlemen earlier mentions, the article mentions, the VMware advanced technical design guide shows, and the video attached the article shows, and as Zachary Amsden from VMware mentions:
vmkernel is started from the Linux kernel.
As does Robin, I invite the author to download a trial version of ESX. They'll find out that both sides of this debate are right, and she is wrong.
Nobody disputes that a Linux kernel is used to start vmkernel apart from Robin.
The question is, does the use of a Linux kernel module to load the vmkernel binary blob means that the binary blob must be licensed as GPL?
As mentioned in the article, Linus Torvalds personally considers such works as derivatives of Linux, unless they're probably not derivatives by having been ported from another platform.
Zachary Amsden has now replied to the article, and stated that he believes that since after the binary blob loads, it is no longer communicating with Linux, the fact that it requires Linux to start does not mean it is a derivative work.
This doesn't really make much sense - copyright infringement for a short time is still copyright infringement - but I invite you to read the full reply in the article comments are VentureCake and make up your own mind.