There's been much talk about how we kids of the 70s were considered kind of a burden, definitely not catered to as the Baby Boomer kidlets of today.
In the 70s, homes were pretty ugly (avocado appliances) and kids' clothes and hair was, too (watch any episode of "The Brady Bunch"). We had maybe five TV channels, sat unbelted in the way-back of Country Squire station wagons, and sure as heck didn't have DVD players in the car...it was either the license-plate game or listen to your parents endlessly discussing Nixon.
That's why the poison-control centers who came up with Mr. Yuk had no problem terrifying us with the creepy music and background images of this public-service announcement. Man, it practically still gives me nightmares today. Two of our cats were in the room when it came on, and the music alone freaked them the heck out.
"Mr. Yuk is MEAN...Mr. Yuk....IS....GREEEEEEEEEEEEEEEN!"