Insofar as any one man has served as the public face of "conversion therapy" over the years, it has been that of the dearly departed Joseph Nicolosi.
Nicolosi, the author of REPARATIVE THERAPY FOR MALE HOMOSEXUALITY (1997) passed away last week, on March 8, at the age of 70.
I've written about conversion therapy, as a legal issue, before in this blog. Here's a link: once you get to the other side of it, scroll down a bit
The above is the stock photo of Nicolosi used by MSNBC. It makes him look like a televangelist, which seems fair.
Apparently the phrase "reparative therapy" was Nicolosi's own coinage, and refers to his views as distinct from some other styles of conversion effort. He coined it because he held the view that (male) homosexuality is a unconscious effort to repair a sense of inferiority.
I really ought to read or at least skim Nicolosi's book before commenting further. But, hey, this is a blog, and ignorance isn't usually an impediment to opinionating. So I'll say this: I'm guessing JN was drawing on Adler, and the old Adlerian notion of an inferiority complex.
I'll quote Adler: "Everyone (...) has a feeling of inferiority. But the feeling of inferiority is not a disease; it is rather a stimulant to healthy, normal striving and development. It becomes a pathological condition only when the sense of inadequacy overwhelms the individual and, far from stimulating him to useful activity, makes him depressed and incapable of development."
So I'm guessing Nicolosi believed gay men feel incapable of sex with women, and seek to "repair" themselves by turning their "striving" elsewhere.
It would be good if this sort of thing were no worse than a tumbling ground for whimsies. Unfortunately, as the history of such therapy indicates, it can be far worse than that.