You are missing the obvious point that infrastructure is a main use of taxes. Do you think roads are profitable?

Rail (& other public transport) has many other benefits, e.g. you'll need less policing and maintenance of roads if they are less used; air pollution from fossil fuels and tire wear are reduced, stress and accidents are reduced thereby decreasing healthcare costs, etc.

It all is a matter of building up the proper network, rather than to give more subsidies to big oil and the car industries (see the eternally repeating bailouts).