I see the Sims 4 as much more pedestrian friendly and I'm okay with that. I also really like to have Sims from different eras in my game, and if cars were added to be more prominent, it would just add more to my struggle to stifle modern technology. :s
I could see them added for the purpose of hobbies or a specific designed location, like a Nascar track on a hidden lot or something, but as far as incorporating them into the general game, I just don't feel it's necessary.