Completely agree. Using a prime lens requires a lot more discipline, and considering that most people ( = customers ) never go anywhere else than full auto mode, why would they bother "zooming with the feet"? It requires a little bit of knowledge to control depth of field. It's not rocket science, but it is very advanced if you compare it to the usual "point and shoot" usage of most DSLR users.

I also have to say that except in low light where more than 2.8 helps, I hardly use my f/1.4 30mm and 50mm primes any more now that I have a 24-70 2.8. Before I used them for very superior image quality compared to inferior zooms, but since usually 2.8 does the trick and this lens had very good image quality, it stays on my camera most of the time.