Eek! I made an anti-aging potion, and now my testers are all babies! I mean, babies are fine vis-a-vis continuing the human race, but these are babies with responsibilities! They have rent to pay! And jobs to do! Ever see a baby try to work a financial spreadsheet?
They're sub-par! Quick, Squishable Witch, I need a magical cream, or ritual, or spell, or apple, or something! Extra points if it also makes them better at financial spreadsheets - they weren't that great to begin with.