I have to agree with all of the sentiments but would truly love some hard numbers. As for the whys, IMHO, there are a number of possibilities that are tantalizing:
Darkroom work is tactile. You handle your end product and shape it with your very hands. John Sexton pointed this out in a seminar and it is very true.
LF is nostalgic. There is an appeal to using 100 year-old techniques to produce beauty. It connects me (however imperfectly) with the masters.
It is Human. When I rely on a machine, programmed by another to do things I cannot do - is it really my creation? When I can so easily modify reality, the serendepity of discovery is gone. How many beautiful subjects have been ruined by power lines or graffiti? When I can so easily change a sows ear into the facsimile of a silk purse, it cheapens the discovery of the true silk purse.
There is, for me, a classic beauty and mystique in the instrument (the camera). It, alone, identifies you as someone serious about your craft.
There is, for me, a real satisfaction that I struggle to master that instrument and that if I approach it casually, I will see that reflected in the mediocre results. If digital backs where 25$, I doubt people would put up with the humbling LF learning curve.
There is, for me, a risk - reward factor. When I trip the shutter, I put $ and time at risk. This forces me to focus, to ponder, to slow down to analyze and most importantly, to look for the beauty in my subject. That is salve for my soul.
One possible conclusion is that while the consumer trend pursues the photo-equivalent of fast-food, a profitable niche will grow. I am becoming convinced that this is the case.