I'd say it is that, plus the fact that they built their charger designs at a time when they had to do them cheap. They had very little capital, and they knew t

I'd say it is that, plus the fact that they built their charger designs at a time when they had to do them cheap. They had very little capital, and they knew that they couldn't sell cars without a charging network. So they put all their efforts into reusing as much as they could from their high volume cars to improve economies of scale. Noone else had the same incentives. That part is changing fast, though.