Isn't this circular reasoning? Rails are terrible, so nobody uses them, hence nobody invests, hence poor ROI. Roads are heavily invested, so are usable to the point it is uneconomical to use any alternative, so roads get more investment, etc.
While in Spain for several months it was only economical for me to take a train a single time. It was several times more expensive than the alternatives in every other case. This left me either flying or bussing.
In Stockholm it's actually cheaper to take a bus to the airport than the train, and that's just local travel.