I suspect it's a cultural thing. A bike that doesn't need to be pedaled proclaims its status as a motorized vehicle. People from a cycling background who pushed for the creation of paths and trails for non-motorized vehicles have a visceral reaction that this is a violation. I know, intellectually, that there is no difference between someone pedaling a bike at 15mph and someone on a silent electric vehicle at 15mph, but I feel that there is a difference, and it's hard to surmount that. I have an even stronger instinctive NO! reaction to the idea of throttle-only mountain bikes on my local trails where there are difficult, technical climbs. Pedal assist can only help to a certain extent, and I have no problem with someone who might be able to pedal up a hill at 4mph being able to make 8mph with assist - but the idea that someone could twist a throttle and cruise up at 15mph without pedaling really irritates me! I realize this is irrational, but when trails are created as a space that is reserved for human-powered vehicles, one wants to keep them that way. I know that to some, even pedal assist crosses that line; to me, pedal assist is still pedaling. And I wouldn't care if someone pedaled a class 2 e-bike, with electric assist mediated by throttle, on these trails - it's the throttle-only usage that would irk. Of course it's easier to ban class 2 bikes than to say, "well, you can ride your class 2 bike as long as you pedal!" And it is easier to advocate for opening bicycle paths and trails to e-bike usage when you can point out that e-bikes are basically bicycles, being pedaled by a human, with a boost from a silent electric motor.