It's possible that you are not the intended audience for such an article, which is clearly targeted at people like the author: a non-expert who is sometimes interested in technical topics. Simplifications, which were indeed abundant, are not the same thing as errors, which is what it sounds like you were implying with "ignorance".

If the author was all, "the thrust-to-weight on a Merlin is like, awesome" and you were like, "but that vacuum ISP, yo!" then you should probably be following SpaceX from nasaspaceflight.com rather than from an eclectic blog.