PG has a related essay: Why Startups Condense in America http://www.paulgraham.com/america.html He actually has several essays on how to try to create a Silicon Valley in other geographic areas, but this seemed the most relevant. tldr: 1. The US Allows Immigration. 2. The US Is a Rich Country. 3. The US Is Not (Yet) a Police State. 4. American Universities Are Better. 5. You Can Fire People in America. 6. In America…
There seems, from my experience mostly in the UK but also talking to people from round Europe, to be a big regulatory and mental impediment in most places to setting up your own business. Being an employee is safe, you get a lot of rights, your paycheck arrives the same day every month and it's actually really hard to lose that, if you are going to lose it that's a huge tragedy, and you've probably had several months notice anyway.
A lot of the middle classes in the UK would never consider trying to start a business, even though the social safety net would catch them to some extent on failure, in reality it may save you from the street but it's not likely to be much better than that. Best stick to that safe £50k a year. Which, incidentally, is considered pretty decent pay but won't leave you much to put aside to actually kick off that business idea later. Starting a business is for high flyers, finance types, other people.
You might be right about it not being lack of energy, but I think the entrepreneurial spirit in the UK is pretty suppressed. And in the EU from what I can tell it's similar, with an added side of "and the state is going to make this very difficult too".