The US has more immigration, for one thing
Yes, it does. Those statistics don't count illegal immigration, and despite that the U.S. immigrant population percentage is still higher than every European country other than Luxembourg and Switzerland (second list), and the immigrants in those two countries are typically wealthy to begin with. Since the comparison here was between the U.S. and Europe, the greater immigration rate does make a difference. I'm not making a point one way or another about the merits of immigration policy, but these are facts that need to be taken into account when evaluating health care outcomes. Has someone found any sort of comparison in health outcomes between insured, median-income, non-obese, non-smoking, non-alcoholic citizens of various countries? Until we have seen this data, how can we separate the gross statistics currently reported into the effects of: a) Access to health care. b) Quality of health care for those with access. c) Lifestyle choices.
You're also forgetting one additional thing:
Driving is focused labor, and riding transit isn't.
Unless you're an incredibly reckless misanthrope, you can't read a book or work on your laptop while making a 5 hour drive. Riding a train or bus you can. 5 hours of getting work done at the rate I bill is a considerable amount of money. Even if I was just reading for pleasure, that 5 hours is worth a lot more to me than the few tens of dollars I *might* save from driving. So unless the thrill of driving the open highway is something you'd pay many tens of dollars an hour for, riding transit makes more sense, all other thing being equal.
The most important early product on the way to developing a good product is an imperfect version.