Though I'm not sure you intended it, this is an excellent summary of why the US doesn't have a decent mass transit system. Even if you get past the formidable political opposition to any public transit system, you must contend with a coalition of that opposition plus an assortment of interests that want a different system, possibly because it looks better on paper (hey, Hyperloop!) but more commonly because it benefits them financially. So in the end, no system is built at all. If the high speed rail project is scrapped, it won't be in favor of Hyperloop. It will be in favor of doing nothing.