The definition of visibility is the ability to see prominent unlit objects by day and lit objects by night.
If there are no objects to be seen (or can't be seen) then it's not VMC.
If there are no "Lit Objects" at night?
You might speak to a Lawyer familiar with Air Law to explain why there is a problem with your offering.
Do not confuse Part 135 Rules for Part 91 Rules.
I do not disagree with the import of your statement....just the way you arrived at it as we both agree about if there is nothing to see outside....you are surely flying purely on Instruments.