Because El Chavo Animado was already a thing that proved to be successful enough.
If anything El Chapulín is a much better concept to work with as a cartoon. He's a goofy superhero who gets into weird situations by designs. In theory, it could be good under the right hands.
Ideally it would be Batman The Brave and the Bold with Chespirito characters. Just imagine Chapulín working with Super Sam to foil the plans of Chómpiras and and El Botija. The possiblities are endless.