That's not really surprising, and maybe should be a lesson to the author. If you want to make a particular point, you shouldn't make inflammatory/controversial statements about other, only-tangentially-related things. It distracts from and dilutes your point.

For my part, I know one of the CoreOS founders, and while I have no opinion on CoreOS itself, it's really off-putting to see some random armchair quarterback on the internet shitting on the work of someone you know. While I more or less agree with the actual real point of the article, the unnecessary attacks really divided my attention.

The article starts off with a cheap potshot at CoreOS, followed by a screed about Kubernetes, and then finally, more than half-way through, we get an admission that the author has "digressed", and we get to the actual point. Certainly the point required some background about Kubernetes, but I can understand why people focus on the negative CoreOS and Kubernetes aspects of the post, since they consist of more than half of the content.