OK, he just went all the way to Victoria Falls to explain what a rainbow is. That just about sums up this series ... style over substance.
You say that, however it's the style that draws in the audience.
I have had it said to me many times before, where is the use in knowing something amazing if you can't tell people about it.
Presentation of scientific knowledge is a fine art, a different balance needs to be struck for different audiences. For a joint venture between the BBC and the discovery channel on a program that was shown at prime time on BBC1, sucking people in with some gorgeous visuals and a compelling soundtrack, while imparting the most important facts about a subject in a way that people will easily remember seems like a great success to me.
Clearly, if you're heavily into the subject already then chances are you already know all the facts, in that case, why not just enjoy your subject being shared with others in a way that they can interact with.
I like to think I am fairly knowledgeable about astronomy and physics and and the like, but I have always found a few snippets of new info in the stuff by Prof. Cox, and in places where I haven't I have always enjoyed the presentation in the same way as I might a good exhibition in a museum.
I really don't understand why anyone could have an issue with this program. Any more substance and it would have turned off a HUGE part of its audience, and frankly without effectively becoming an academic lecture, a little more substance would have done nothing to turn people already knowledgeable more onto it. They struck an excellent balance.