I think in most cases, the fantasy is far better than the reality. The idea of the exam, the submission, the exposure, the control, all erotic elements of a fantasy, appeals to many men. I think that there are other issues too, though.
One is that as men, we ike it when other men notice that we have a hot wife or GF. We know men would love to see what we see.
Perhaps some men even go as far as fantasize about sharing their GF with another man. In this case, a GYN exam is a safe way to do that. Sex is not going to happen, but at the same time, there is a certain trust and often a somewhat sexual tone to the gyn exam. It is , after all, about private sexual organs, sexual function etc
I have many times watched my wife have these exams. She did not mind that I was there. She knew I enjoyed it for whatever reason, and I knew she did not. Most women, I have found, from working in the med field, hate gyn exams to some degree.
My wife was not into med fet but was accomodating to me at least. I have not gone with her in a while though, and the excitement that was once there is not as much now. The exams are always quick, professional, and follow a set standard of practice. Nothing was ever done which would be considerably innapropriate, and according to her, she has never had a bad or innapropriate experince with a Dr. (Unlike some)
She does not seek out gyn exams, and I have found that more times than not, a doctor who is not a GYN (say a GP or family Doc) will NOT offer or recommend one, other than to say "Go see your gyn" The reason, clearly, is that if someone does something and finds something wrong, then he or she must then pursue treatment of it; also medicine is so specialied that it is far easier to send someone with a certain complaint to a specialist. Maybe not as "fun" when a hot patient comes in though ...
Perhaps too, for this reason, I find it more erotic when a family Doc gives her a gyn exam for whatever reason than a gynecologist. At the GYN office, it is expected; but a family doc does not do as many, so maybe this is more of a treat or more of something unusual for him. Especially with a wife who is the model type. One gyn exam that she had from a family doc of some repute seemed to take twice as long as any other. Maybe because the guy was not as skilled, or maybe he was just having fun. Who knows Erotic for me? yes, seeing her exposed while another man looked at the pleasure zone, wishing and dreaming he could have what I do....
For her, not really, in fact she made us stop seeing him after that exam.....