What is the antonym of insightful? I want to say that the information provided is not insightful. I searched in various dictionaries. The most common antonym is unperceptive, but that does not exactly carry the meaning of un-insightful.
You could use
pedestrian to imply that any old Joe off the street could have thought up the same thing. Obvious is the word the US Patent Office uses to indicate that an idea isn't original or creative enough to be patentable.
For someone who flat out doesn't come up with much in the way of ideas at all, the term used the most is probably
Obtuse - lacking in sharpness or quickness of sensibility and intellect.
The adjective insightful is defined as
exhibiting insight or clear and deep perception
Antonyms of this are: shortsighted or unperceptive, unperceiving (also the words others mentioned: superficial, obvious, shallow, trite; notice that it depends what you are denying insightful observer and insightful observation have different antonyms)
On a side note, I believe that you can coin a word with no problems i.e. in the spirit of the English language: insightless (and you would not be the first)
May I suggest the word banal?
So lacking in originality as to be obvious and boring.