Many still shoot color neg because it gives them the option of getting both if they want or require, it was quite common at the lab that I worked at to have customers request both B&W and color from the same neg.

By the way, many of the new printing systems will do it through the computer included in the machine as well as print color positives and b&W positives from Color Slides, albeit not the same quality and tonality ranges, but it is a pretty easy process, with machines like the Noritusu 2900 RA-4 Paper processor.