Here's the problem, yes its batteries, but really its still about targeted markets, not creating a viable electric vehicle. Harley does it as a trendy item and like the Zero will be limited production items. Pulling from the same article both you guys quote:
'The riders coming behind Harley's core customer are a very different breed, belonging to one or more of four categories: they're young -- 18 to 34 -- female, black, or Hispanic. You may have noticed Harley starting to cater to this new customer, what it calls its "outreach" customer.'
Zero's not without its own issues; having experienced multiple recalls on their lithium battery packs and sell at a price point much higher than similar performance gas burners. Besides, these units are not bikes! they are DOT controlled licensed motorcycles. With Zero; however, you're working with a company that's primary focus is totally electric vehicles--not the same for Harley. So I expect that Zero will invest more in long term development than Harley. Still, its not a bike, no pedals so why try to make an ebike a motorcycle?