It seems like the more appropriate question when discussing these frameworks might be whether they are useful. Many people find the MBTI framework a useful way to think about themselves. Just like many people find GTD useful for being organized, or Paleo useful for choosing what to eat, or Agile useful for coordinating software development, or [system/lens/framework here] useful for [thing that people do], even though they are not demonstrably "correct" (or even superior to competing systems).
Correct and useful aren't necessarily the same thing, especially when we're discussing systems that are more of a descriptive worldview than an actual set of predictions.
The Big 5 is the current standard, and the four MBTI dimensions correlate to 4 of the Big 5. E/I is Extraversion in Big 5, N/S is Openness to Experience, and the other two are less orthogonal, but generally T/F is Agreeableness and J/P is Conscientiousness. Neuroticism in Big 5 is essentially not measured in MBTI and doesn't correlate well with any of the MBTI traits.
I did not see any peer reviewed journal articles by him on personality in a Google Scholar author search for his name, only books and a single conference paper.
Finally, looking at the most recent CV I saw -- http://www.darionardi.com/webcv.html -- only one of the papers in the "personality" section is actually from a journal, and it is, lo and behold, a Type-centric journal. And half of the conference papers are for the Association for Psychological Type International.
As appeals to authority go, he is a poor one.