Most of this thread has been how to do pelvic floor exercises [PFE], not about the original question--do they make a difference? The answer to this question is more complicated, based on what I've learned, than we might think.
The word on the street, as reflected in this thread so far, is that PFE helps.
However, it's very hard to prove this is the case. In fact, clearly many people do PFE faithfully, whether "correctly" or not, and still have some (or unremitted) incontinence. This is also reflected in this thread.
And it is also the case that scientifically there is at least some question as to whether too much PFE or PFE done wrong might actually negatively contribute to continence.
So is the surgeon (as originally quoted) right? Perhaps so. Although like many such technical experts, he might not have been politically sensitive to his audience. In the meantime, we as a community should probably take these thoughts in and wonder whether they are right or not, rather than being confident that what we think is true or experience as true is definitely true.
My own experience was that I was remarkably continent, so either the PFE was amazingly effective or, alternatively, the PFE was not in fact the most significant factor for me. Now if only that had worked for erectile function!