It might have been a hoax by the CDCCDA, but for a completely different reason--playing the long game. Keeping monsters scared of children keeps monsters from touching children, or interacting with them within arms-length.
Because here's the problem with children: they grow up into parents.
I remember being afraid of monsters as a little kid. My parents couldn't do anything to help me, either. But in the years since then, I was able to convince myself that they weren't real, just creaks, tricks of the light, and my own overactive imagination.
Imagine what would happen if I, and my whole generation, remember monsters getting up in our face at night, and us being able to see them clearly, and us knowing, without a shadow of a doubt that they were real.
When my daughter was afraid of monsters, my experience told me that they weren't real. To help her, I gave her a flashlight that turned on for a minute every time she squeezed the trigger. If I remembered that monsters were real from my childhood, I would have been sleeping on her floor every night, curled up with my Louisville Slugger. A generation of parents like that would have put Monstropolis into an energy crisis for a century, easy.