Bikes are optimized for cost and ease of riding (i.e. less weight when possible), so bikes avoiding bells and whistles by default makes perfect sense to me. If you add on too much then the bike shop prices themselves out of the market.

Bike ridership IMO is much more heavily determined based upon how bikable a space is. If it's an environment where you don't have access to safe roads/trails, nearby destinations, or places to lock your bike at a destination no one will bike. The bikes themselves may have quirks, but that's rarely the complaints people voice in the wild from my experience.