Lets not forget Porsche generally and the GT variants specially are actually among the lightest sports cars on the market. At an average 2850 pounds Only the Speciale and the 650s come close weight wise and those 2 cost a lot more, almost double.
Im sure they could make them lighter if they really wanted but that would take them out of their target price range. They've only recently switched from steel to aluminum with the 991. Not possible to switch to an all carbon tub for a car as mass produced as the 911.
The 2010 Cup car weighed 2650 pounds while the same generation RS only wighted 220 pounds more. That's impressive if you ask me. The current Cup weighs a little less even though its bigger. My biggest disappointment was the weight on the 918. Its one hell of a car but the weight is a bit BMW.
Im not sure where im going with this
A perfect example of marketing shoving stuff up the engineers throats are the current 21" wheels on the latest RS. I don't want to guess what a new set of MC would cost in those sizes.
About the GT3 customer. Speaking from local experience, almost 80% of the older gt3 owners were track comers. Some more than others. However with the current 991 gt3 that has significantly changed. It probably at 50% or less now. PDK made the gt3 an easy attractive option. I see a lot of them mostly on the streets.