The accounts I've read indicate that it was a financing problem, mostly. Games got a lot bigger in the 90's, companies started merging and getting public listin

The accounts I've read indicate that it was a financing problem, mostly. Games got a lot bigger in the 90's, companies started merging and getting public listings and there was a general "corporatisation" of the landscape. This massively favored the US companies going into the CD-ROM era since it was easier to find investment capital there. The UK's early talent advantages and successes in gaming were brought about by a combination of heavy investment in computer education at a national level and a market structured to support the marginal(the ZX Spectrum was an extraordinary price sensitive market - cheap machines, cheap tape media, "budget" game pricing), but once the games got bigger, most of those companies were quickly reduced to subsidiary roles since they weren't able to make the same big bets on production, and this reflects the dynamic across tech in Europe generally: it's just harder to build a big business. I do suspect you're right about the dynamic with open source as well. Programmers who are purely mercenary have tended to gravitate towards the orbit of SV for the past twenty years, but Europe offers more opportunities for career open source.