They may just be balancing out structural deformities in the upper body, but let's look at another possibility. We live in a society of people who are usually very uncomfortable in their bodies. A word like sex was only said aloud in a whisper for decades. Times have changed nowadays. They've actually changed to the opposite extreme.
People still have issues with physical contact, just on the other end of the stick.
There has not been much of a balance. To rebel against an issue, the issue must first be a part of your life. And I think in some cases, this shows up in the adductors as a sort of chastity belt tightening. A discomfort with your own physical body and it's expression in life. Let there be no misunderstandings, I am not saying to go release this through sex.