Brash on a personal blog is tricky. In this post's case, I'd worry that the blogger has a hard time separating technical deficiencies from professional incompetence. "Designed by amateurs" is an over-the-top and dubious claim.
As an experienced engineer I can hear the pain behind that dubiuos claim and no, I wouldn't want to work with someone who behaves like this all the time but I wouldn't mind someone who once in a while gets fed up show some emotions. It's all about how you handle the aftermath, ie. can you apologize to people you accidentally hurt along the way.
Their goals were not to create the most academically sound type system. They were focused on engineering challenges. Read the comments here ti understand the authors' priorities and obstacles.
