I'm guessing with how many summoned heroes they've got they realized not only were they so weird personalitywise, they were also weaker than the demon army even with cheats, they eventually just raised native heroes that were more powerful then the cheat heroes and... voila.
It would be funny if all these summoned heroes came about cause there's a king/minister back in the day that had some summoned hero fetish. 💀
I like your spirit, but I fear that pro-tomboy efforts are being coopted by fans of musclegirl-lite content, those malicious or unaware of their one true attractions.