That's actually what pedal-assist restrictions are all about, clearly delineating the bicycles from the motorbikes. This also manages expectations for users. You shouldn't expect to play in traffic at 60+kmph as a cyclist, and you shouldn't expect to be riding your much heavier, much faster electric moped on bike paths.
The form factors can make that line blurry, you could totally have a bicycle that can do 60+ and you could easily have a moped that looks small enough to be a bicycle. Hence the regulations to clear up any confusion.
From a personal exprience point of view, I would expect to be able to comfortably wear leathers and a moto helmet and not negatively impact the ride. On a pedal assist bicycle there is no way I am wearing leathers and because of that I don't want to be going 60-80kmph in traffic unprotected, I want to be on seperated bike paths.