The Vette and Viper are COMPLETELY different cars, and are marketed completely differently.
The Corvette is a mass produced high performance Coupe, that has been built in high volume for nearly 55 years. There is usually an option for a higher performance model, at a higher price and much lower production number.
The Viper, on the other hand....has one goal. A crazy ass exclusive super performance car...PERIOD. Either you can afford it, or you can't. I think the ACR is the only real "upgraded" Viper they've made in addition to the normal ones, from the factory.
I think it would ruin the name and image of Viper if they made a watered down version that was mass produced and cheaper.