Because we like consistency?
I very much like the idea that there are very few places with an M next to my name.
Is that needed/required? Perhaps not, but I have a ton of things in my life that are about preference. For instance my panties. They could be tighty-whitey jockey shorts. No one sees them, and for 99% of my clothing, it wouldn't matter. And, they'd be a lot cheaper than the panties I actually wear. But I would know. For most of my life, it was important that I knew me, even if no one else could even see me. Even if no one ever sees the BC, I would know...
Kate