Except this only helped the folks living close to big train station hubs, across the country there are plenty of places where the car is the only viable option.
Yes there are places where cars are better in some aspects, but that is the case no matter how the ticket is structured. You can't magically extend the train network by reducing ticket price.
And if cars are the only viable option is questionable, as there are many people even in those places who don't own a car. They just have to live with subpar bus system or other local transport.