Nigel,
Just because it is legal does not in any way make it the right thing to do. That attitude is what gets people killed.
What kind of safety culture are those operators operating within that can justify that? Day, VFR, VMC....is one thing but night over open water is a completely different matter.
It is time for pilots to get their collective heads out of their butts and do like Ma Regan suggested...."Just say No!"