Anyone arguing EV depreciation that ignores the tax credits is seriously slanting the picture. With tax credits my car was only $35,500 last year (loaded '14 Giga with 19's). Being told that its dropped to $28,500 after a nominal year of ownership is only a $7,000 reduction or 19.7%. I can live with that. And if you aren't planning to sell it any time soon, then its a moot point.
As for why anyone would "buy" a car, maybe some of us plan on driving it for 6 or 8 years as it meets our needs. I've got no problem with anyone leasing, especially when the manufacturers are offering ridiculously cheap leases in the US, but personally, I like having no car payments for a substantial portion of my ownership. After 6 or 8 years, I'm not really worried about the resale, and I'll look for something else.
I'd probably feel quite differently if I was having problems with my i3 (I'm not, btw), but that would be the case no matter what car it was - BMW, Merc, Chevy, Kia. I had a Saab that was reviewed by Consumer Reports as the "best car Saab has ever made" when it came out. My car had a seemingly endless stream of annoying problems (computer, water pump, fuel pump, constantly burning out headlights, alternator, etc.). If you get a bad car, you'll never be happy. If you get a good one, you're content.