Other than the fact that there are several American firms who have already done it, and even if there was a knowledge deficit it’s the easiest thing in the world for an American company to headhunt foreign talent. Too easy in most industries.
Opposition to new railways is political, be it from establishment organizations or private owners, like in California. That’s all there is to it.
Which ones? Which company actually has put out a consistent, significant, structurally sound high speed rail network including stations and the trains themselves that is based in the US?
And headhunting foreign talent tells me that you have not worked in the rail planning sector. These companies are extraordinarily protective of their high value who are the executive “talent” behind their stuff. And the biggest rail tech companies are multinational conglomerates (Alstombardier, Siemens, CRRC, Hitachi) who have no desire or need to outsource to America.
There is noone currently who has both intimate knowledge of American geodetic planning and high stress track planning. And building that knowledge takes a lot of trial and error.
https://en.m.wikipedia.org/wiki/High-speed_rail_in_the_United_States
While their current average speed isn’t great compared to the highest speed rails in Europe and Asia, it is comparable to the average high speed services, and Amtrak seems confident in their claims for Acela in 2024.
Just so we’re on the same level here - your own article states that high speed rail as it is most commonly referred to means speeds of above at least 200km/h, more commonly beyond 250. Lower speeds are “higher speed rail” in America, or regional/local lines in Europe. My local lowest tier urban mass transit has a normal speed of 160km/h.
America has ONE Line with speeds beyond 250, and that is where all except one of its 200+ speeds lie aswell. That is, sorry, a joke. For one line a network does not make.
Look at that same graphic in the article on the high speed network in Europe and tell me they are even close to comparable.