I think some people overdo the use of black & white photos. It has its place, but I think it needs to be a highly selective thing and not the focus. Too many photos are diminished by eliminating the colors in them.
But to each their own. If someone is happy with their results using primarily black & white, then why should I care?
I know the excitement I feel when I capture an image that's close to what I am seeing. If another person feels excitement with black and white, that's great for them. I have a few photos that I think are enhanced by black & white or where it's needed to communicate the mood of the moment.