[zaph0d_]

I would not consider the language barrier as the largest obstacle. But the European scientific infrastructure can't even compete with Californias institutions and it gets much worse if you count in the whole US scientific infrastructure. Most of the world leading scientific institutions like Standford, Berkley, CalTech etc. are located in an area where scientific knowledge can get appropriate funding for a product. You simply cannot innovate or create something new without extensive research from universities or research labs. This is one of the problems.

The other problem is, in Germany at least, that the general population is not that well educated in computer science, since the educational curriculum is organized in a strict federal way. The German constitution even prohibits the state from cooperating with the federal education departments. CS should now be a major subject on the same level with math and physics, yet this kind of system makes it very hard to implement a curriculum for all of our pupils. This causes, that even a lot of young people are not that interested in CS and lack of basic CS knowledge.

[jitix]

This is a bit tangential and only based on recent events, but the US immigration uncertainty is probably going to be a factor in sustaining the ecosystem..