I don't know why Wayne doesn't want any gun mounted lights, but I know why I don't put a light on my gun: it violates too many safety rules. Pointing your gun at something, then turning on the light to see what it is is a VERY BAD IDEA.
I understand the concept, but don't necessarily agree. There is enough indirect light that you can still make out your target, you don't necessarily need to be pointing the firearm directly at someone.
Also depending on the light hold technique being used it matters a lot if you are coming off the right, left, top, bottom of cover/concealment. For instance to clear off the right side of cover/concealment with the FBI hold (for a right hander) may mean you light doesn't even clear cover/concealment. This means not only might you not illuminate your target, but blind yourself and light yourself up.
...........just goes to show that like all things firearms there is almost never one thing that is "best" for all situations, there is always some sort of compromise.
BTW as much as many people don't like to mount lights/lasers on pistols, the same argument is not made for doing the same with a shotgun or rifle......