1) US and EU economies nearly equal each other in size. [1]
2) You only need one language in the US to reach the entire market.
3) I don't believe for a second there isn't prejudice against outsiders in each individual European country. Wikipedia hosts an article written just about tensions regarding Polish people entering the UK! [2]
1 https://www.cia.gov/library/publications/the-world-factbook/...
2 http://en.wikipedia.org/wiki/Anti-Polish_sentiment_in_the_Un...
2) Well, i18n is nothing hard these days, at least from a technical perspective, also you could reach certain market types using only English quite well in Europe.
3) Yes, this is true, however these problems are visible only in small parts of certain tiers of society. Shortly, the chances of meeting people who openly display negative sentiments against foreigners are smaller if you run a company consulting about GIS, than if you are a plumber/gas station clerk or whatever.
Also, by "'you dirty outsider' attitude" I meant that attitude being displayed by the government, which is very typical in the US.
For example I am a software developer, who comes from one of the 'new' countries and currently lives in another 'new' one, but I have spent significant time in an Western European country and so far I haven't had a single problem with bureaucracy (and with drugged-out undereducated unemployed youths with too fragile minds as well) at any of these places, which compared to Entchev's case of 'they got my entire family under arrest and ruined the life I have been building for the past 20 years' is a whole world of difference.