I use color film like a seasoning in a gourmet recipe throughout your wedding day. There isn't one simple answer to that question. Shooting without a flash is much less intrusive for the subjects involved. Intimate moments aren't disturbed like they would be with a flash. The next reason is a bit more personal.
Color photography is reality based.
When we look at a black and white photograph, we don't view it like we would a color picture. Instead of being caught looking at the colors, we focus more on the subjects and their emotions. Also, that ugly 70s wall paper in the background now becomes just wonderful tones of gray. As an artist, it allows me to concentrate fully on my subjects and the moments they're creating. I'm not worried about a bright red something in the background that's going to become a distraction.