I think a lot of this stuff is due to the attitude of the general population towards entrepreneurs. If the only question that matters to people is "Have you made any revenue yet?" there's probably not much hope for Europe ever catching up with the US in terms of new fast-growing tech businesses.
(I'm hoping the UK is something of an exception, but I'm not really sure. Lots of people here are still very sceptical or pessimistic about new tech companies, especially very small, innovative ones.)