Why do you think public transport is horrible in comparison to cars? Do you feel that e.g. the environmental or cost benefits of public transport are outweighed by whatever cars have going for them?
Public transit takes longer, is less reliable, doesn't let you leave when you want, is often dirty, is harder or impossible to bring a lot of stuff on, and is more likely that you'll end up a victim of a crime on it than while driving.
None of this is true for somewhere like Tokyo, except for the 'harder or impossible to bring a lot of stuff on'. You could say many of the above for cars depending on the place (try driving through Jakarta for speed and reliability or many parts of India for safety).