That's a load of HorseSh*t, BK. Yes, you engage the motor by turning the cranks. But, it's really no effort at all. A chimpanzee with one leg, could get an ebike up a very steep grade. And therein lies the problem. On trails that are primarily downhill oriented you have riders with a limited skillset, completely in over there heads, ascending, at speed, up a trail. Add in a blind corner and you have instant head on collision potential.
Other trail users such as hikers and equestrians have for years been opposed to us on trails. They lobby hard with deep pockets to close what few good trails we have here in the west. EBikes and their inherent conflict potential, only adds fuel to the fire.