I strongly disagree with this. I've owned an electric scooter for over a year now and I learned real fast that it's super dangerous to ride on the sidewalk.
The problem with pedestrians is that they are not looking out for scooters. People will wander into your path and depending on how fast you're going you may collide.
Also you can't see people walking out onto the sidewalk from doorways and recessed building entrances and around corners. I see people on those scooters going full speed on sidewalks and if someone happens to suddenly walk out doorway they're getting hit.
When people walk out onthe street they should look both ways for cars before stepping on the road. In my opinion it's ridiculous to expect people to peer out of doorway stoops and look for people on scooters barreling down the sidewalk.