alt Hacker NewsCheaper, quieter, smaller footprint for storage, can be easily brought up a few stairs or put in the back of your car (by one person), slower (a perceived safety advantage by some, as most motorcycles can go highway speed), maintenance is less daunting (again, perceived), culture (perceived) as some people are quite turned off by motorcycle culture, and many many more.
One of the major problems with ebikes is the existence of cars and related infra.
Motorcycles have all those advantages against cars, except being able to bring them indoors. Yet people aren't all riding around on motorcycles. E-Bikes have their niche, but they're not going to replace cars, since motorcycles didn't.
Motorcycle culture is something you choose if you participate in. If you're a lady commuting to work on a scooter, few people will expect you to participate in that.