To use your example: Denmark is not really a huge country, Romania has 5 times the surface area and ~4 times as many people, not to mention the huge economic difference between the two. It's much easier to focus less on cars and build high speed rail when you are a smaller and richer country.
> Cars are a failed god.
This is a hyperbole, people still want to own cars and have the comfort of leaving home whenever they wish and going directly wherever they want to go instead of exchanging buses and trains as well as waiting in between these in order to get from one place to the other.
Specifically for Romania, though I'm sure this is true in other places as well, public transportation inside cities needs to be nailed down before looking at things like high speed rail systems - companies have an interest in their employees getting to work on time, the state would spend less on healthcare if the cities were less polluted, and people would rather wake up a bit later in the morning.
I believe that in the future we'll still see roads being developed alongside rail and high speed rail or other solutions, regardless of how many people think roads are a failing concept.