have we been reading the same manga? first of all, when did the author make the mc a 'good and moral' person? the only thing the mc has been thinking about from the start, is saving himself, and meeting his waifus. on top of that, it really obvious that, while he is not dumb, he is not exactly the sharpest tool in the shed, which means that the mc just didn't think about it that deeply. Besides, this manga is a COMEDY. Any way, the mc is in the body of a child that was conducting rituals to his maid, and that also means that his physical brain is of that child, is it that hard to think that he is influenced by his body?
You basically claim that japanese authors are bad at writing, when you yourself can't even pick up the details, and if we go by your opinion, then the mc would simply go out of character.