A Last Ride?

Why is there such opposition to funding for Amtrak? Reading blogs or responses to articles about Amtrak reveals such a negative opinion of support for a national rail system (because that's what it amounts to) boggles the mind--or my mind, at any rate. The latest flurry I just finished reading was an unmitigated rant about taxpayers paying for others to ride: if I don't ride Amtrak why should I be taxed for those who do? If I don't have a car, why am I being taxed for roads to be constructed or maintained? That aspect of reasoning never seems to have occurred to those who oppose funding for Amtrak.