I know what you’re saying – “How is Play Dough evil?”
True, in its natural form it does not seem very evil. But put this recipe in the wrong hands (or the right ones?) and they will be able to mix up their own dough at any time to copy keys, full-sculptured make-up… even models for future engineering feats.
As you can see Sinister chose to make a scorpion – a guardian for his own evil genius lair. Nefarious chose instead to perfect his canon balls, including throwing said canon balls at said guardian scorpion.
Play dough – not an evil weapon.
But the experiment of making it – ever so useful in the grand scheme.