NO it does not make any sense. They are designed to fit two different segments of the market.
Air = Ultraportable and good specs/$ ratio
rMBP 13" = rip off for trendy wannabees
Just a Retina display isn't the computing solution to everything and for everybody.
I personally like the Air and would go for a maxed 13" if I needed portability and performance. Retina display? no thanks for now, we all survived without so far and now it seems that if you don't have it you're using clay tablets like the Sumerians...
I initially preferred the box-shape of the MBP, then for whatever reason got an Air instead, and NOW an loving the extra thinness (carries like a tablet), and the extra lightness. It just feels like a tablet except with a real keyboard. Spoiled. I would have to carry the 13" rMBP for a couple of days to decide now.