Why don't QBs wear Visors?

I couldn't do it. I have headgear for sparring, one with a clear visor and one with just bars to protect the face. The visor slows my reaction times. It affects my hearing, vision, and makes me feel just a little claustrophobic. I don't know about all the laws with a dark visor but I guess it's just preference. I know some guys I spar love the visor so go figure.