Because,realistically that segment of the market is not big enough for a company recovering from a very recent bankruptcy to worry about. I am surprised that they are even bringing the Viper back so soon. What you are talking about is a market that is OWNED by the mustang,which has built up a 46+ year following. It would have to be something very special to even have a chance at competing with the mustang.
The only thing OWNED by mustang is the school girl v6 market.Would you prefer them to sell just the econo cars like the dart that your complaining about.Brining the viper back is a good way to promote thier mopar power image again.