The problem is you can't get there from here. The costs to build a rail system where it doesn't exist are very high, and until you have most of the system in place it is useless to most people.

Of course we built a road system - without paved roads cars are mostly useless. We have build rail systems in the past as well. The problem isn't unsolvable by the nature of the problem. It is unsolvable because you can't get the right people to make long term investments in it (don't look to government - anyone who tries will be voted out eventually at best the system changes course from one okay system to a different incompatible system, though more likely they just stop investing).