I would venture to bet the percentage of Tesla drivers - and by extension Prius drivers, heck all PEV and HEV - that acutally care about being "green" in terms of actual climate change is quite small. I encounter people who are enamored by the technology of Tesla rather than the environmentally friendliness of it. Admittedly, I myself am in that category. But I'm also a great example of how alternate incentives, stimulus, and broad appeal can bring people on board with climate change - whether the individual is an activist or not.
I didn't purchase solar or an EV because I wanted to be green; I bought it because of stimulus, incentives, and a long term view of cost reduction. To that extent, this deal excites me.