Something like back in the 40's, Grampa Herbst started a gas station, had great service, offered more stuff than his competitors and so they started saying stuff like "That Terrible Herbst"......the name stuck. Thats what I heard anyways.
A google search goes a long way...
The Wonderful World of Terrible's
Carwash company spreads like wildfire through Nevada desert
By Sara Cooper
Many know him as "the best bad guy in the West." He is the gas-slinging Wayne of the Nevada desert, black hat flattened squarely on his head, charcoal moustache drooping below the chin, daunting eyes glaring ahead. He is the symbol of a company that doesn't mess around when it comes to running a business--and running it big time.
Terrible Herbst, a gas station, carwash and casino giant with 65 profit centers in Nevada, California and Arizona, was founded by Ed Herbst in Chicago in 1937. The business got its name because of the turmoil that would arise whenever Herbst moved into a new area. The local competition, afraid of losing business to this crowd-pleasing operation, would warn one another to watch out: "That no-good Terrible's coming to town."
Not only did Herbst feature low prices, but also free pony rides and bubble gum for the kids, orchids for the ladies and women on roller skates to pump gas and work under the hood. Ed entered the service station industry with an attitude of innovation, well reflected by his creation of the first self-serve gas station.
MORE AT - http://www.moderncarcare.com/articles/1b1Cover.html