Yes, the GTO is way too heavy and has very narrow rear tires (245's), otherwise I think it would sell better. They can make a car with convenience features and not make it overly heavy these days if they really wanted to. Sound deadening doesn't way all that much and if you look at this pic of power vs manual window actuators(from my Dakotas), the weight difference is very minimal. The motor is maybe an extra 1 or 2 lbs.

A muscle car does not need GPS navigation or fancy 6 disc changers. But it doesn't have to be bare bones. Bucket seats and power windows/locks. What more do you need when there is a 6.1 under the hood and a 6 gear option in your right hand?? Ok, maybe a cup holder! ;-)