The Volt is a HYBRID (with a bigger battery than any hybrid). That car will use the battery only mode as a gimmick, and then go to gasoline operation when it feels like it, to save the battery and not discharge it to any great extent in order to keep the number of discharge cycles low. I personally have a 12 year old Hybrid, and it still works find. So this car doesn't count.
Inaccurate facts and faulty reasoning. The Volt works fine in "battery mode" for many people. Just as with TMS, it depends on how you need to use the car. The only reason I don't consider the Volt is the cabin design.