The justification is that a jpeg of a waifu is worth more than a jpeg of a husbando and it's easy to hand wave a genderswapped version of a historical figure into existence because their core demographic just wants waifus to fawn over anyways.
I'm glad some people here were willing to go into a fun discussion about the narrative reasoning, which in my opinion are interesting reasons for the character's existence and circumstances. I appreciate conversations and people like this greatly.