You are treading on dangerous ground if you're trying to promote any single type of bike as the "ideal" commuter.
Anyway, yes I commute for exercise and no, I don't want to commute on the heaviest bike I can manage. It's really not so hard to understand. If I'm miserable the whole time I'm exercising, guess what? I'm not going to stick with it very long. If I enjoy it, the opposite is true. So when I work hard, I want to be rewarded with speed. I don't want to feel like the bike is holding me back.
The truth is that I commute by bike for multiple reasons:
- it's better for the environment
- exercise
- don't have to pay for parking
- enjoy cycling and bikes
- like being outdoors
While still much better for the environment than driving, an e-bike is not as good as straight human power. I'd also get less exercise on an e-bike as already mentioned. Further, I enjoy bikes because of the simplicity of them and the thrill I get from moving fast under my own power. Don't you remember what it was like to run like the wind as a kid? I get that same feeling on a bike.
The reason you're getting some push back is that you asked if cost was the primary reason why people aren't commuting on e-bikes. When people provided other explanations, you questioned their validity. Instead of really wanting answers to your question, it feels more like you're trying to sell people on using e-bikes, - Europeans are doing it, so it must be a good idea, right?
I think it's great than you're enjoying your converted bike. I also really enjoy my fixie, but I fully expect that if I started a thread extolling the virtues of fixies, I'd get much the same response you did.