I have pondered long and hard about how to reply to this or whether, indeed, to reply at all. Firstly, I was not trying to make a funny, political, anti-US or any other sort of derogatory remark. Also I never said that this derailment had anything to do with track quality. I was merely stating that the more practice that you have at something, usually the more efficient you get at it. Maybe, "poor infrastructure" was a poor choice of words. If you have low(er) grade lines then the likelihood is that at they may fail, the more line you have the more failures there will be, statistically.
However, what I really objected to was being talked down to. I'm a railroad enthusiast who models US railroads. Of course, I know that UP is larger that the British rail network. Of course, I know that there are 6 major railroads in the USA. I model CSX. The fact that the US has different types of operators, from short-line to Class 1, the fact that it operates on such a variety of trackage, over such differing conditions is what makes US railroads so enthralling. From street running to two mile long trains to two CSX ET44's pulling three freight cars, who could not like it.