Hey Duncan,
I live in Denver with a heavy bike culture as well. So far only 1 fred got upset in the last 2 years (4000 miles), but I think most everyone else either
a) is unaware
b) doesn't care
c) keeps their frustration (naivety) to themselves
At work it is a little different since a relationship exists and I use it to commute. Either they don't understand and think you get NO exercise or they purely look at biking as a sport, like soccer instead of a potential lifestyle which ebikes could help everyone realize! Overall its just fun joking though, from my point of view.
On the street most of my interactions have been on the questioning side like: "How does it ride?", "How many watts is yours?", or "Do you like it? I am thinking of getting ....", but even these questions rarely happen. Mine is relatively stealth though.
My response to all of them is basically: "Best money I have ever spent! Period." I couldn't imagine a better way to travel!
Either way, who cares what other people think? Biking is awesome, and having the option to add power when needed/wanted is amazing! I haven't driven a car for an errand or excursion outside of a road trips in basically a year! If everyone knew the possibilities it would be a hit!
Cheers!