What qualities prevent a question from being "insightful"? (Meta but still an appropriate post, I hope)

Yes, this in inspired by a recent post by someone else, and I'll avoid answering this question in the text with my theories, but, to elaborate:

1. Are there certain TYPES of questions which are inherently not insightful? If so, how or why?
2. Are certain PHRASINGS of a question more or less useful for generating interesting discussion?
3. Are there CHARACTERISTICS of the person asking the question that somehow prevent the question from being as interesting as it could be?
4. Are certain BEHAVIORS of the OP in the comments indicative of the above questions?