The problem is, our cities (most of them) are already designed for cars. To change them to accommodate walking and public transit would be somewhere near the largest sociological project the world has ever seen. It would require upending every single aspect of everyone’s lives in order to refit them around walking and public transit. I think it’s unreasonably infeasible at the current time.
Maybe people on the right are less likely to seek out help from mental health professionals. People on the left have less reservations about it, and therefore see more diagnoses.