Loads of precedent. Even though Kodachrome became the first practical colour medium in the mid-1930s, it was unsuited to studio photography and printing. Kodacolor was introduced in 1942, but with an ISO25 rating, so it was ill suited to the local photographer's shop as well. Instead, there were Marshall Oils—transparent colours—and a vast army making a living doing hand colouring. As it has always been, photographers have sought the most practical means to meet the market's demands.
During my first decades, I shot mostly B&W, not for any photographic advantage, simply because that was all that was practical. Few colour presses existed, and printing colour in magazines, newspapers, flyers, brochures or books was extremely costly. B&W ruled, simply because of technological and monetary considerations. Colour was only used when content warranted the cost—it was reserved for the best.
For the past three decades, I have shot nothing but colour with very rare exceptions. If B&W was assigned, Panalure was a panchromatic paper, exposed and processed in total darkness, that provided extremely high quality prints off colour negatives. Standard B&W filters could be used during the printing process instead of on the shoot, providing higher sharpness and quality.
In the digital world, I shoot colour exclusively, even when shooting IR. Some of my stuff still ends up B&W, if a client demands it, or if I want to affect some hipster-ironic image supposed to be from the past for, effect. When I do so other than on a client request, my tongue is firmly in my cheek! I regard anyone who shoots B&W—specially myself—as doing it as an affectation. In a time when colour is so critical and so well achieved, there is little reason other than affectation to ever shoot monochrome. Leica certainly understands the wealthy hipster mentality, and his happy to stick them with a camera that can not shoot colour at a greatly inflated price—and the hipster will pay for it. I am sooooooooooooo embarrassed for them!
