[ims]

You're talking about whether the MBTI framework is correct, or verifiable, or scientific. That's interesting because the context for this whole discussion is around a rationality checklist which may not be correct, or verifiable, or scientific.

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.