But pure sports? There are parks for that.
Don't get me wrong, I'm all for reclaiming cities for pedestrian and bike travel and creating a maximally energy-efficient public transport system (ironically, the best idea would probably be self-driving, publicly-owned electric cars forming a PRT network). But in current situation one has to stay pragmatic.
We should be promoting cycling not making it even more difficult. Self driving cars can make cyclist significantly safer for everyone. The most dangerous thing on the roads right now is human controlled cars.
I love to go on long bike rides. Like 4 or 10 hours long. Parks is not an option for that. While backroads are awesome. Once out of town, I usually meet a car once in a while. And while in town and suburbia, I guess I can qualify as A to B commuter. Even out of town, sometimes it's sort of A to B commute, because I want to go to some sightseeing spot or fancy cafe in the woods or smth. I just happen to cycle instead of drive. Or sometimes I dispatch my family in a car and go by bicycle myself. It's still A-to-B, isn't it?
Saying what is and what is not a "proper road use" is a very slippery slope. Is it OK to drive to get to a grocery store? Is it OK to drive to some spot in the middle of nowhere for sightseeing? Is it OK to drive for few hours to bbq in an unseen place? Is it OK to drive to go fishing in a nicer lake instead of the one nearby? Is it OK to drive to see friends if you can video call them instead?
I myself spend more hours on public roads on a bicycle than driving a car.