Why is it called a wimpy burger?

I'm curious, why is it referred to as a "wimpy burger"? Is there a specific reason behind the name, or is it simply a playful moniker? Does it have something to do with the size, ingredients, or flavor of the burger? Perhaps it's a nod to a particular cultural reference or historical context that I'm not aware of. I'd love to learn more about the origins and significance of this intriguing name.