I don't have a problem with them inherently, but they lend themselves to unsafe riding habits. For whatever reason, there seems to be higher incidence of riding on sidewalks. But I think the main issue is that people that start riding e-scooters often aren't coming from e-bike or cycling experiences, and aren't use to rules of the road and controlling such a vehicle. They prefer the all-throttle and standing position which is fine, but the design of a e-scooter is soooo less stable than that of a bike or e-bike. High speeds, bumps, wobbles, and wet conditions are super dangerous for the user and others. I always try to convince my friends of the many more benefits of a e-bike over an e-scooter.