On my commute, it is easy to spot the e bikes. They are flying and do not slow down. When they are approaching, I need to be careful in the event that they will be passing another bike or runner and veer into my lane. I need to slow down and make sure that they can pass safely because they will not slow in order to pass only when it is safe. It is rare for a rider on an electric bike to slow down even in a congested area. The last few miles of my commute is on a heavily used section full of families, pedestrians strolling and parking lot entrances. Only someone with little experience riding a bike would think it ok to ride at 15-20 miles per hour swerving between kids on 16 inchers and dog walkers using extend a leashes or racing through the exit of a parking lot where happy hours are popular. The 10 percent that ride e bikes safely is an exaggeration.

edit: The difference in behavior of e bike riders and cyclists is very noticeable on my commute. Of course there are the "racers" on road bikes who use the MUP for "training" and the "kid" with the Beats carving Ss across the whole path. But these are 1 in 50 and not the 9 out of 10 regular e-bike riders on my commute.