Потому, что "непризнанный гений" -- мужская фигура. На всем протяжении спектра "непризнанных гениев", с обоих его концов (от заслуженно непризнанных до незаслуженно).
Более развернутый комментарий в комментариях, по-английски:
Men may be interested in the ontological and epistemological status of what they are doing, for its own sake. Not all men, not anything like a majority of men, not even a large minority, but quite a few of them. Women are much less likely to be so interested. Women are interested in the social status of what they are doing.
Now, opinions as to the epistemological status of fermatist writings may vary, depending on who you ask (the fermatist himself, the professional mathematicians, various segments of the public at large, etc.) But everybody knows (as a matter of common sense, experience, conspiracy theorising and whatnot) that their achievements or "achievements" are not going to be socially recognized. That should suffice to make women uninterested.
In other words: men are stubborn and romantic. Foolish, to put it bluntly. Women, much less so.