Heck, why don't we just make it IFR?
As anyone who has done real NVMC flying can tell you there are times when you have to be on top of your IMC skills, out in the GAFA on a moonless night (killed an ABC film crew in a helo near Lake Eyre), or try offshore on a moonless night, you can see SFA, including horizon, beyond your warm cocoon.
WTF does the visual bit mean if I can't look outside
It merely dictates the weather necessary to conduct the flight, a pitch black night the first indication you'll have of flying into a cloud will be the reflection off the cloud of the anti collision light.