The UK tech companies found it hard to export to the US
Because, at the time, the US government would only buy from US tech companies, and most big businesses had their purchasing decisions strongly influenced by what government bought (often for interoperability reasons), which influenced small businesses (for the same reason). Marketing in the USA required a big budget to get national penetration and there wasn't an obvious place to start.
In contrast, a tech company in California could start selling locally and then just expand slowly into more states. Their existing supply chain didn't need many modifications to sell things one or two states over. A British company trying to sell in the USA needed to establish a foothold somewhere. They needed to ship either components for assembly or completed devices to the USA.
Selling to mainland Europe required translations
Is that a big deal? Especially if you went for a few major languages, like German, first. I would think that European manufacturers would have been more used to the need for translations than American companies.
P.S. Wish I had mod points to bump up your post.
For a small company, the cost of translation can be the difference between making a profit and making a loss. You need a big investment to sell enough in France or Germany to recoup the cost of localisation. In contrast, a US company had an English-speaking audience on its doorstep and so could ramp up to economies of scale in the tens of millions of units before they needed to consider localisation. At this point, the incremental cost is sufficiently low that it makes economic sense.