I've noticed that people who don't identify as bikers are more and more opting for an ebike over an oldskool bike by default (and bikers too, as another steed in the stable).

I don't think this is a bad thing for public health. Ebikes need pedalling too, they just assist. They assist quite a lot, which makes them fun to ride, and probably makes them more enticing to take out. The fact that they assist means you can go further in the same time, which is certainly what I witness happening amongst my bikehead friends and the people I meet in the mountains.