I can only answer for me.
1. Black and White is inherently more abstract than color, a greater departure from "reality," so it encourages more variety of interpretation on the part of the viewer.
2. B&W emphasizes form over color, so if the forms in a scene are more important than the colors, a B&W conversion enhances that.
3. Color sometimes distracts from the main point of an image. In another thread, for example, Russ Lewis (RSL) has posted both a color and a black-and-white version of the same scene, an old mining sluice. To my eyes, in the color version the foreground color dominates and makes it difficult for me to see the rest of the image. In the monochrome version, the whole scene comes together much better, IMHO.
4. I made my own black-and-white chemical prints for almost fifty years before joining the "digital revolution." It was great fun for a while to print things in color on my Epson 2200, but I quickly tired of most of it and yearned for the richness and mystery of B&W. So now probably 90% of what I print is in B&W.
5. The old masters who were active when I was getting into photography (Edward Weston, Ansel Adams, Minor White, ...) did virtually all their work in B&W.
6. Up on wals in my house at the moment I have 17 of my own framed prints. Of those, 13 are B&W, 3 are Color, and one is mostly B&W with one section in color.
7. A final point: I'm what is called "color-blind," or more accurately, I have deficient color vision (garden variety "Red-Green" type), so I don't see colors the same way most others do (but roughly 5% of all men see colors the way I do). But Black-and-White looks (I think) pretty much the same to me as it does to others.