I think you summed it up pretty well knnn. I also think if you went on a hiking website, you would find similar sentiments there about mountain bikers - and id agree. That's why there are threads on here encouraging mountain bikers not to be entitled pricks when they interact with other trail users. That's also why I slow down or stop when I interact with a hiker on a multiuse trail. We also have threads on not braiding trails and not being a strava douche. Users here have varying views on these topics - That's the point of a forum.
That being said, you are an ebiker posting in a cycling forum. If I went as a cyclist and started posting in hiking forums, I'd probably find many hikers who weren't all that crazy about mountainbikers. That's not to say all mountainbikers are douchebags, but I suspect their perspective would be, as you put it bikers "are or should be considered douche bags until they prove themselves innocent"
I have thought a lot about ebikes as they seem to irritate me and I have tried to figure out why. There seem to be two things that get under my skin about them.
#1 they want to be considered just another form of cycling. The bikes are marketed as the "evolution of cycling." Sorry, I just don't agree. It's motorized. The fact that it is a shitty little motor and the throttle is built into the pedals doesn't make it a bike. A simple mod, and you are riding what was in the video posted. That being said, I'm happy ebikers like riding their motorized bikes, but it's not a bicycle.
#2 because ebikers want everyone to consider them cyclists, they also want to be entitled to all the trail/path access cyclists have. I don't agree with this either. We have all been worried that the trail access that has be so hard to earn will be ruined by adding motorized bikes, especially as they get more powerful or as people mod them. What this video demonstrated to me is that as motorized bikes are added to trails, mountain bikers probably won't be penalized, it will actually be the ebiker with the wimpy motor. If we see lots of electric motor contraptions all over hiking and biking trails, the knee jerk reaction will likely be - no motors; period.
My comment was simply that it is not my responsibility as a cyclist to protect the trail use rights of ebikes. The people who should be worried about bigger and more powerful ebikes/emotorcycles coming along are riders like you who want access to non-motorized trails because you opted for a motorized contraption that has a wimpy motor and the throttle in the pedals. If electric motorized contraptions become a bigger problem, no one is going to care what type of motor you have, they will just end up banning motors I suspect.
Your last comment was that you didn't think there should be a special onus on you as an ebiker to maintain access to the trails. I find that weird. Mountain bikers have only gotten access to where it is through hard work and promoting the activity. Ebikers will have to do the same for themselves. In the early days of ebikes (that we are still in) trail access is not a huge issue for you all because the ebikes are only starting to get powerful and the numbers are low. As numbers increase and especially the number of people riding things that resemble your ebike but are way more powerful and have a throttle on the handlebar, you may find that your access becomes in question. Same thing for city paths and bike lanes.
Your activity is in its infancy and where it ends up is anyone's guess. The only way it ends up somewhere you want it to will be through advocacy, and the onus is on riders like you if you want a say in it.