Because Japanese authors (specially of the power fantasy genre) are major p*ssiesWhy didn't she kill them by suffocating them with water magic?
I'm pretty sure that villains in this manga will always be absurdly evil. Right from the beginning, her parents were special cases of scumbags (and you also mentioned the corrupt guild member) so the writing was on the wall.I don't think this story needs villains like that in the story to make it work...Like, the overly-obvious-corrupt guild-member that tried to fuck them over with the loan or w/e, was also a really badly written villain....
That was my way of saying: "It wasn't needed then, it's not needed now".I'm pretty sure that villains in this manga will always be absurdly evil. Right from the beginning, her parents were special cases of scumbags (and you also mentioned the corrupt guild member) so the writing was on the wall.