When my local supermarket, the retail stores, restaurants, etc. have bike parking that is secure enough that I don't have to worry about a $1500 e-bike getting stolen, I'll get one. But they don't offer it, so I don't.
As an aside, in my opinion, electric bikes are probably the most practical form of transportation available right now for most urban communities. They climb hills, go pretty fast, can offset the rolling resistance of fat confidence inspiring tires, are smaller and easier to park than a motorcycle, are easy to charge, and have a manual backup in case of battery depletion. I love two-wheeled transportation in all its forms and think the electric bikes that are on the market now are an awesome middle ground between motorcycle and push bike.
I've participated in bike related web forums, and talked to a lot of people about cycling. I'm trying to be somewhat of a bike evangelist without being too annoying. What I've learned is that like unhappy families, cycling stories are all widely different, and each person has to figure out a way of adapting to their own circumstances. For some, it's bike parking / theft, like you say. For others, it's arriving at work, drenched with sweat. Weather is an issue. Even specific routes have their own peculiarities. Traffic is a huge deal.
I'm seeing a lot more e-bikes.