My guess is that it's because most of them put you in the role as the witch protagonist, which traditionally is good-natured.

When the witch is the antagonist, they tend to be more of the traditional kind.


Also there's just this huge boom of indie life sim/farming games that just lend themselves to a wholesome tone.

BTW Withering Rooms is on my list of games to play, so I'll get to it at some point