I guess I can spin it if I want to make it not look so bad. It's like how people do things they're not supposed to all the time, and if you do that as a kid and something bad happens to you, even if it's a coincidence, you can still expect someone to tell you that's what you get for doing whatever it is that you did. The moral doesn't stop the girls from using their powers for personal gain, like Will cheating and making an Astral Drop to do chores and Cornelia making herself look older to get a guy. So it actually subverts the moral of the day episode cliché, both because the moral doesn't make sense and because they ignore it anyway.

Having the Oracle or someone else punishing them would be more of a heavy-handed thing, and this way it makes sense that they wouldn't learn a lesson and refrain from such behavior: the events of this episode don't really teach the purported moral, so why take them as a cautionary tale?

But this is purely me making something up to justify the episode.