I certainly don't want people feeling like they're being forced into making inferior choices - just that we make an effort to design our towns and cities so that the choice to walk/bike/use transit is a realistic one that compares favourably with driving.
I think people just don't realize on gut level how fast driving is... someone mentioned Edinburgh as a place where it would never occur to them to drive. As it happens it was 5:30pm there when I plotted a random trip out of the city center to some residential area, it was 25min in "red" traffic vs 43min by transit, not counting overheads of waiting of course - so realistically x2 faster and that's from a city center. That was also my experience wherever I lived or visited, except rush hour Moscow where traffic is completely unreasonable and transit is good (although at rush hour very crowded, so reading is also questionable)... you'd look at "terrible traffic" and wince, then you look at transit directions and drive/call a cab cause it's way faster anyway :)
Which I'd wager includes a sizeable fraction of the population. I also remember seeing a study in Germany some years ago where they found that exclusive car commuters had the highest average BMI and bike commuters the lowest. Granted, it was not a massive (ahem) difference, but definitively a few kilos…
"sedentary lifestyles" is not a real externality and anyway is also easy to achieve with transit; "time wasted in traffic" is simply false (far more time is wasted on transit given how fast it is to drive for an average trip, and sometimes even in rush hour), "dominance of cityscape by infrastructure dedicated to automobile traffic" by itself is a totally fake - it's a subjective aesthetic preference.
Now as for the actual real externalities, I said elsewhere, it's one thing to say "most people reveal the preference to drive (and I disagree with them OR because driving is just better), however they cannot all have what they want because of pollution / global warming /...". That could be correct, although it would also imply this is a technological problem - they mostly solved pollution from cars, and if we e.g. had cheap fusion or solar energy and electric cars we could all go back to driving.
It's quite another to pretend that people need to switch to the inferior (by their own revealed preference around the world) lifestyle because it is "objectively better".