It really boils down to 2 things. First is the obvious comfort, they think it's more comfortable to be in a car. But that is broken down with traffic. You bring up traffic and they'll complain for hours about it.

Second is fear. They won't admit it but they're just terrified because they just hear of the big bad city and think stepping on a train is a one way ticket to getting stabbed, while never having any real knowledge of what it's like.