From a quality of life point of view, I have never been comfortable being crammed into a sardine can with that many other people. I've done it. I've never enjoyed it. I do look forward to travelling to the Netherlands one day and I will enthusiastically use public transit there just as a personal experiment to see if my experience differs enough from the subway transit in Montreal or Toronto that gave me nightmares and has me thinking every time I travel there: "Even if it takes me 4x as long to get to my destination, driving is still better than this."
The parent poster made an interesting point that resonates a lot with me. Better public transportation will get people off the roads which will make quality of life better for drivers. I don't see myself ever not being a driver. I need that little bubble that separates me from other people. I don't even like walking on sidewalks in busy metropolitan areas because of the amount of other people and the "over stimulation". And yeah, that's a me problem. Do what you like, just don't take away my means of being able to achieve a little bit of solitude.
It's not pro- public transit and better urban planning that bothers me. It's the anti-car "lobby".
Then again, big city living isn't for me anyway (obviously). I will always choose smaller to mid sized cities, and possibly even rural at some point in the future, for the personal reasons outlined above.