My problem is that you are making a generalization about black primer, implying that everyone will have the same problem you have. That's just not the case. You make that claim based on your experiences and your technique. However, it doesn't take into account other people's experiences and techniques, which by all accounts are very different from your's. Sure your technique is fast and produces good results, but it is by no means the only technique nor the best technique.
It doesnt matter what color primer I use, it takes me the same amount of time and effort to get a model to a state I like. My preference is actually for gray right now as I can see details easier when painting, as white and black make details more difficult for me to see. Other than the short speed improvment gained from seeing the details easier in the first place, prior to putting on my base colors, my style doesn't change how much effort it takes to get to a final product I'm pleased with.
For you, white is best, for someone else black is best, but I find it highly unlikely any one will ever be able to prove that one color primer is always best nor one color should never be used. Please just stop claiming absolutes.