I don't know anything about the above, but I do know that whenever I take a survey, the choices often do not include my answer. Sometimes any answer I give will be misleading. Surveys can be constructed to give false results even if the selection of participants is legit and participants answer as honestly as they can.My guess would be that Nissan, like a lot of car manufacturers, does it's research using marketing research firms. These firms typically:
1. Tell the company paying them what they thing the company wants to hear.
2. Use a "pet" set of "subjects" that very likely don't represent the actual purchasers of the product. (just ask any long-time Prius owner)
3. Even if they don't do #2, the subjects are likely to give the tatemae answer rather than the honne answer because they think that's what's wanted.
(tatemae means public, official, or politically correct, honne means private or the way things really are).
I'm not surprised if environment weighs heavier than operating cost when buying an EV. When cost is the main factor, the choice is always a used car. For me it's environment + the personal pleasure of a smooth, quiet car. Considering the relatively high cost and short range of the Leaf, again I'd think the environment is a bigger consideration than cost savings. Oh, yes: Convenience (no gas stations) is a big one also, though in the case of the Leaf that's balanced by the inconvenience of not being able to "fill up" in five minutes virtually anywhere. There's also the fun factor. Even my little Zap Xebra was the most fun car I'd ever driven before I got the Tesla.