because he was the product of his evironment. he grew up in the romantic era where no one talked about sex. it was only intended for male pleasure, and in some cases was a necessary evil for reproduction. women weren't allowed to talk about it to their female friends, or even to their husbands. because it was so hush hush some people repressed these feelings and sexual dysfunction took over. Freud was no exception. he had wierd sexual desires, and when he started doing therapy he found that others had similar dysfunctions. the problem is that he over generalized these cases. sick people need help, and all these people seeing him were sick in some way. he failed to realize that the greater part of society didn't have sexual dysfunction, but he choose to believe that the small sample of people he did therapy with represented society as a whole.