My two cents (and it's worth just about that). A $30K electric motorcycle is doomed to fail as a mainstream machine. That's just too much money for mass adoption. So I think that using the Livewire as an example that electric motorcycles will fail isn't a really good measure of how electric motorcycles will do.
Harley was right up front that they did not expect to sell many of these machines. They think that the Livewire is almost like a "concept car". It's supposed to grab people's attention to the brand. I don't agree with that, but that's HD's philosophy.
HD has a bunch of smaller, lighter electric bicycles, scooters and motorcycles coming at a far more approachable price point. They are gambling that the Livewire will make their other machines more well known and desirable.
Again, I don't agree, but that is indeed their plan.
Will electric motorcycles succeed in the long run? I think question boils down to technology. If battery tech can provide electric motorcycles with as much range as gas powered machines, the internal combustion engine will be lining up with the dinosaurs.
Climate change, whether you believe it or not, is quite mainstream. Younger people are far more concerned about it than the baby boomers. Baby boomers are going to die off and hence, the remaining buyers will be those younger and more ecologically concerned people. They'll opt to go green. Even if it costs them in utility.
So I'll put up a nickel and say that electric motorcycles and other forms of electric transportation will succeed.
Which will bring us to our next greatest challenge, how are we going to generate the required power to charge all these electric things? At the current technology levels, solar can't do it, nuclear is a no-no, hydro has ecological impact and wind turbines aren't "pretty" and kill birds.
It's a puzzle with no picture to look at for reference. So maybe electric isn't the cornucopia that we might think it is?
I think I'll start working on that cold fusion reactor in my shed this weekend.