I would think most people are comfortable with the idea that appropriate colour vision is necessary in order to be PIC at night.
The question is why are those who are CVD precluded from obtaining a night qualification or IR?
There is absolutely no need to prevent anyone from obtaining these qualifications. A simple requirement on the medical certificate for a safety pilot to be on board at night would seem to resolve the safety issue.
It is another example of mindless proscription.