Well, that is my paraphrasing of this author’s post.  The Myers-Briggs test is common throughout many business-world assessments and it serves a purpose.  The difficulty I have always had with it is the binary aspect of the assessment.  You are either Extroverted or Introverted…there is no grey area.  I think the author explains it well:

More problematic, though, is that it classifies personalities by a binary preference for a particular trait. In reality, however, most people exist on a spectrum between the two and can vary between them from week to week…

Agreed.  People are the ultimate variable and far from binary.  I think the best use of the Myers-Briggs assessment is to define preferences, but not to make hiring decisions based off of it.

If you are looking for a reliable assessment tool that does provide grayscale depth, I recommend our DISC-based, Selling Style Assessment (more details here).