Johnny Boy, I'm open to the idea that you can have superconductors for which BCS theory doesn't apply. In fact, We know that for high temperature superconductors BSC theory doesn't apply, so this must be true.

As I wrote earlier here, I'm not an expert in these matters, I read the book by Rickayzen a long time ago. However, if you claim that all of the BCS superconductors are in fact not correctly decribed by BCS theory, you also need to explain why BCS theory does make correct predictions, like e.g. the isotope effect etc.