It's like they hired very fearful, superstitious, judgemental, and unprofessional maids on purpose. If you think about it, if you were an adult and serving a young mistress who never does anything wicked and doesn't bully or harshly punish anyone for honest mistakes, what kind of idiot would keep treating her like a monster? It would make sense they would be afraid in the very beginning (though if they were professional, they wouldn't show it), but why would they be after a while?
I guess it's really hard to find good employees in that kingdom.