How’d they get such language past the censors on network television in the ‘70s?

The word goes way back before the 1970s. I did a search on here. It was used on Lost in Space.

Dr. Smith: (to Robot) "Mind your manners, ninny, or you'll lose your friends."

https://www.sitcomsonline.com/boards/showthread.php?p=5950429&highlight=ninny#post5950429

The complete phrase of cotton headed ninny muggins was not allowed though.