I agree with Kirjava, everything you've said is either well-known or blatantly incorrect.
Anyway, it is unfortunate but things are not always named after the person who *invented* them, but the person who popularized them. This has nothing to do with America or Fridrich, it's just the way the world works sometimes. Why? Well, the people who invent methods don't always promote them. Sometimes somebody invents something and publish it, but 20 or 50 or 100 years later someone re-invents it and cannot (or does not try to) find the previous published work. Wikipedia has a whole big
list of mathematical theorems that are named after someone who was not the first to discover them.
Here's how the history goes in speedsolving: in 2003 people who didn't have all the old 1980s books (many of them weren't even that old) wanted to learn to speedsolve, and a big movement blossomed. So people want to learn a fast method... where do they go? Fridrich had a webpage which was around for many years already, describing how she had a 17 second average (very fast for the time!) and explaining the method with plenty of algorithms. I think Lars Petrus's site was also around at the time, but he didn't claim such fast times, and his LL system was more basic. So people started using Fridrich's method - not the method Fridrich *invented*, but the method Fridrich *used* and explained in great detail. I don't think I remember it explicitly referred to as "the Fridrich method" on the website, but shorthand names like that take hold just because they are shorter. After enough years, of course, it's hard to change the name, and Fridrich is quicker than Treep-Dockhorn anyway, so you'd have a hard time convincing everyone to change. Think about this: even though Treep and Dockhorn invented the method, I don't think it's a stretch to say that Fridrich as a person was far more important to modern cubing. In the first few years her method and website acted as a guide to how to be fast for very many of the early cubers, really the first very advanced tutorial on the web. Your conclusion might be "LOL FRIDRICH IS EVIL FOR HAVING A METHOD NAMED AFTER HER" but I say "Fridrich deserves the name because she contributed more to the method and to modern speedcubing than Treep and Dockhorn did".
This isn't an isolated case, as I've said. Remember Erno Rubik? A handful of other people applied for patents similar to the cube at around the same time. Larry Nichols patented a magnetic 2x2 in 1970 (granted 1972); Frank Fox patented a spherical 3x3, in 1970 (granted 1974); Terutoshi Ishigi independently invented the 3x3 design in the 70s as well and was granted a Japanese patent in 1976. And yet we call it Rubik's Cube, because Rubik's design was the first to be mass-produced, and he got his name on it as a result.