Long-term, the sale of these cars is allowing the EV market to mature. Already the price of the batteries has gone way down. The nextgen EVs coming out this year and next with 200+ miles of range were only made possible by this "unsustainable" consumer good. Maybe my 2012 EV with 75 miles of range is already in a land-fill somewhere. But a car like a Tesla S keeps its value surprisingly well and should last for quite a while.
The Chevy Bolt is a compelling car that someone could own for a decade. Your main complaint is that the cars are evolving so fast that there are better options available every time your lease is up. Big deal!
I think the battery is the most hazardous component. It's also the most valuable from a recycling perspective.
Firstgen EVs are not popular in the aftermarket: http://blog.caranddriver.com/tesla-aside-resale-values-for-e...
Battery recycling is an emerging market as well: http://www.greencarreports.com/news/1093810_electric-car-bat...