Arguments in the U.S. about rail often center on the vastness of the U.S. compared to individual European countries.
However, Europe is about the same size as the U.S. (or bigger depending how you compare) and has generally better rail across the entire territory, this renders the argument fairly moot.
I don't see any mention of the US in the article. Not any "why can't the US be like this", not "let's contrast Europe to America": nothing. I guess some people just want to guide any topic back to their own America.
As opposed to another comment[1] which brings up the issue of rail in California. You just post some images which are comparisons -- according to what? Because I got the exact opposite impression of you intention -- that you meant to say "See, the US is crazy big so that is why we can't have nice things like fast rail!". Are we supposed to guess both the issue you are alluding to and your own stance on it from no introduction at all? Did you accidentally post your post as its own comment instead as a reply to another subthread?
(On the matter that you are referring to -- Europe is pretty densely populated overall, except for places like the Nordic countries north of Denmark. One point in the US' favour is that it is a single country.)
You may have noticed here on HN that conversations often expand beyond the confines of the article. I'm sorry you're unable to bring in knowledge of this topic from both the article and other sources, and an understanding of arguments pro/con for both European and American rail, into the conversation and provide productive commentary.
https://mapfight.appspot.com/europe-vs-usc/europe-united-sta...
vs. All of the U.S.
https://mapfight.appspot.com/europe-vs-us/europe-united-stat...
For fun, here's a similar-ish map for calculating travel time in the ancient Roman World.
http://orbis.stanford.edu/