The source of the unhappiness is not so much the commute itself as what it deprives you of. When you are commuting by car, you are not hanging out with the kids

The source of the unhappiness is not so much the commute itself as what it deprives you of. When you are commuting by car, you are not hanging out with the kids, sleeping with your spouse (or anyone else), playing soccer, watching soccer, coaching soccer, arguing about politics, praying in a church, or drinking in a bar. In short, you are not spending time with other people. I don't think that's it exactly. The problem with driving, especially commuting in traffic, is that it requires your constant attention but offers little mental stimulation. It's a boring section of life that you can't zone out and fast-forward through. Walking and biking are also (often) solitary, but I'd expect that people enjoy them much more than driving.