People of modest income can't own glorified golf carts for daily transportation. They need a dependable, all-weather vehicle that can make short or long drives to and from work and for personal drives. Their $6000 will be spent on a good used car, pickup, SUV, or minivan.
Behind all the posturing about fuel efficiency, there are two kinds of people promoting use of these vehicles on 30A: Well-to-do folks who want to venture out of their neighborhood at the beach in their golf cart/buggy/LSV (call it any name you want), and those with a commercial interest in selling or renting those same vehicles. I'm just guessing here, that those who fall in the first group aren't trying to help reduce our carbon footprint by driving a Prius/Volt/Leaf as their primary mode of transportation.