One main difference between Europe and the US is that wealth concentration in America is much, much higher than in Europe. This is one of the main forces behind the VC scene: for a multi-millionaire, throwing a few hundreds here and there to some young gun is nothing, even if you lose them all you'll still have your Porsche and your boat. In Europe, wealth is more distributed, which means that, for many, a bad invest…
There used to be great entrepreneurship hubs in Europe... in the 1500s. Wealthy europeans are more likely to invest in experimental art than experimental businesses nowadays.