Complex sentence: When "Itchy and Scratchy" are cancelled, we see a long montage of the kids of Springfield playing in a wholesome maner, which is a satirical point by saying the opposite of what the writers believed.
Split into simpler sentences: When "Itchy and Scratchy" are cancelled, the kids of Springfield resort to playing in a wholesome maner. The montage was a satirical point by saying the opposite of what the writers believed.