Peyo apparently struggled with the Smurfs adaptations, however, as Americans (in their typical fashion) tried to make every plot about money:
> "One key problem," said Delporte, "was motive. The Americans might envision a Smurf inheriting money, which then filled the other Smurfs with envy. Or they would picture a Smurf finding some treasure and these riches causing problems in the village. Or… a Smurf would try and sell Papa Smurf's secret formula. Everything they proposed, every plot, revolved around money."
Peyo tried explaining that, for his characters, gain and greed were not even concepts. But these explanations were received as unthinkable. Says Delporte, "All they did was mutter behind Peyo's back. The view was 'This is all so sweet it's giving me cavities.'"
Culture clash. The Smurfs were originally just a sideshow, much like the Minions today. What's interesting is that the Smurfs world is already quite rich in and of itself and all of the characters are super funny without bringing in more elements from our own world. It's clear that they live more than a few hundred years ago. The way they interact and the various story lines as Peyo put them out probably simply don't appeal all that much to an American audience. Just like the Marvel/DC Comics universes (and everything that gets dragged into it, it's like a black hole) don't appeal all that much to me.
Including some hilarious ones like the smurfstrijd/taalsmurf, a play on the Belgian issue of language.