At least in the pacific northwest, mounting biking isn't just about riding the bike any more than owning a motorcycle is just about riding a motorcycle. It's a culture or talking about and bragging about bike tech. Weight is bragging rights for mountain bikes as "aero" is for road bikes. Lots of people will pay to have the better toy. The running joke is that many bikes are worth more than the cars that bring them to the trailheads.
I think your confusing regular mountain biking with ebikes. The people bragging about bike tech will most likely be looking down at people that ride ebikes on the trail.
