Angry Turtle
Contributor
I am NOT a fan of black/opaque skirts on masks -- especially in dark waters -- almost precisely for the reasons people give for liking them -- they block too much light.
a. Want to see if your buddy is still beside you? Check the reflection in the corner of the mask -- often you'll see either the bubbles which are wonderful light reflectors -- no change in position (head or otherwise) -- just a quick swing of the eyeballs.
b. Need to signal your buddy? Sometimes, due to ambient light or other issues, shining your light onto the mask is the best way (or only way) of getting attention. The black skirt prevents that. (And no, by using the clear skirt, the light is just reflected giving the person the notion there is a signal -- not a blinding of light.)
I don't get people who want to cut out light -- light is good!
It is all about the conditions where you dive the most. All your arguments are good for low light areas. When I dive, it is mostly sunny in tropical or subtropical areas. Specially in the shallow, even with a black skirt I find myself squinting to keep the sun from my eyes.