As a traditionalist, I believe the only place for motors in cycling is hidden in the downtubes of cheating pros ...
Seriously, though, I think they're great. I don't anticipate getting one anytime soon, but then again I just bought an "all-road" bike and had to talk myself into getting it with gears, so .. ya know ... baby steps. I do know that there is going to come a day in the not so distant future when I either have to start replacing parts of me or adding parts to my bike to be able to keep moving. The latter seems cheaper, so I'll probably go that route. Will that include a motor? Don't know, but I wouldn't rule it out. I rode one on a bike tour out in La Jolla a couple years ago and I had a huge smile on my face the whole time. There is just something inherently funny about pedaling at maybe 50 rpms and still going 20+ mph uphill. Anytime I even see that it cracks me up.
I do think there may be a question of viability for shops considering including them prominently in their lineup, though ... I think the jury is still out on that. On the one hand, it could bring in new customers altogether. But on the other, there's the possibility that the market just isn't there. I'm not exactly local, but in my own area, most of my encounters with ebikes seem to be in the stores that sell them - not so much in the spaces you could ride them. There's a Trek store out near KoP that seems to have gone all in on ebikes and I'm not sure how that's working for them because I rarely see them anywhere around here. Every now and then I'll see one on the Schuylkill River Trail, but I've never seen one in Wiss, Belmont, Green Lane or any other trail system I ride regularly. I'm not sure if they're legal or not because it's never been a thing to me, but I do think that ebike users in places like Belmont especially are going to face an uphill battle with access because they'll have to demonstrate that they can control their bike at speed in very tight and twisty conditions with lots of log overs and such. The terrain here might be a limiting factor. Some other spots - like French Creek Rattling or anywhere in central PA - are just too technical to make a 50 lb bike with a motor a viable option. So it's possible that ebikes could become a thing here more for road riding than off-road. But I could be totally wrong on that. Maybe everyone is buying them here and I just don't see them because I'm too wrapped up in my own analog world.
(Question: if a regular bike is considered "analog", what is a singlespeed? Is that like listening to a victrola with an ear cone?)