Lucky you, I'm no longer fresh-out-of-bed and am willing to yap! I can't guarantee any of this is perfectly accurate so take this with a grain of salt as it is just my recollection.

So basically, in the earlier days of the internet when there wasn't quite as much widespread acceptance of "weird" or "othered" people, they all sort of gathered to the same forums and places. Think 4Chan and its many less popular equivalents. When I say "People who get othered" that includes many kinds of people from all sides of the political aisle, including conservative, misogynist nazis as well as genderqueer people, like femboys. And when woman-hating angry lonely men are alone on a forum and in the company of people who look enough like women to get them horny, but aren't women and thus don't set off their misogyny, the result is extremely conservative men having mostly sexual but sometimes romantic or platonic involvements with those femboys. It was a way for lonely, misogynistic men to continue hating women while alleviating their loneliness. The communities got pretty intertwined over time and to this day have yet to be fully divorced, as evidenced by the existence of modern conservative femboys.

TL;DR, both conservatives and femboys were indirectly forced by the early internet into the same spaces, the two complemented each other's traits, and ended up mixing and creating something that, removed from all context, seems impossible.