I think saying "go kill yourself" is wrong. I prefer "go fuck yourself" if someone wants something strong and rude. I think that "go kill yourself" makes a status claim, as in, "you are not worthy to live", which is too easily believed. I think that's why saying 'hari kari', which reverses that to be 'you are too honorable to continue living', is more acceptable in American culture.
Nevertheless, there are examples of people saying 'go kill yourself' in American culture, as in:
Bill Hicks, to a class of people: “If anyone here is in advertising or marketing, kill yourself. ... There's no rationalization for what you do and you are Satan's little helpers. Kill yourself, seriously.” - http://www.youtube.com/watch?v=gDW_Hj2K0wo
Rush Limbaugh to a specific person: “Mr. Revkin, why don’t you just go kill yourself and help the planet by dying?” - http://www.cjr.org/the_observatory/limbaugh_suggests_nyts_re...
A court decides that it's protected speech with no implied physical threat: "Using various pseudonyms on Twitter and on blogs, Cassidy published more than 8,000 tweets and posts about Zeoli often wishing death upon her. (One tweet, for example, read, "Do the world a favor and go kill yourself. P.S. Have a nice day.") ... The judge in the case, Roger W. Titus, agreed with Cassidy's assertion, concluding that the First Amendment "protects speech even when the subject or the manner of expression is uncomfortable and challenges conventional religious beliefs, political attitudes or standards of good taste." - http://www.cnn.com/2011/12/16/tech/web/stalking-on-twitter-p...
A quick examination of these plus 40+ written by people without any influence shows that 1) it is less used by politicians and people who are actually in a position of power, and 2) it is strongly accompanied with a sense of superiority.
This leads me to wonder if that "800 Europeans" you mentioned come from a culture with strong subgroup differences, wherein people from the other group are considered 'less worthy.' While in the US, there's a relatively strong cultural desire to remove those subgroup differences.
However, a third category of people is comedians, who manage to get away with it because it comes across as a joke. Based on what I've seen by Torvalds, he quickly comes across as exaggerating to get a rise out of people. This, many people are going to ignore that asked of what he says, because they know he can't seriously mean it.