Good question BSA Biker.
Best part of 20 years in 'Yrup' tells me the elements of a service economy that I got used to while living in the US of A, or before that in the UK, are quite hard to find.
It's not maybe surprising there are hassles with imperial bits and bobs as there is such a small market. BUT it amazes me it is easier and FAR cheaper to obtain, eg, old series metric threading tackle from the likes of Tracy Tools than it is from here, where the stuff was invented!
I never try to get any British m/cycle parts here, ever. And parts for other machinery are also usually far easier to get, and better-priced, from the UK or the US.
Not sure how other European countries rate. I've had great service from Hungary on occasion, always first-class from Switzerland as you'd expect, and good also from Germany and Austria. I wouldn't swap where I live, no way - but it is frustrating sometimes. Luckily, as an English speaker, with the www at the tips of the fingers, it's not so hard. But for my mono-lingual French friends, restricted to what they can find on the internet in French or with Google Translate, it's harder. Especially for the very many of them who aren't yet used to concepts like PayPal, online payments and banking transactions.
Even within the so-called 'developed' world there are massive differences in approaches to commerce it seems. One hesitates to make any comments about who's ahead and who's behind, but where I am reminds me of 20 years ago, with the exception of having now-reasonable (ie non-dial-up!) internet speeds! All very charming - until you need something!
It's not because we're furriners though I don't think, or not here anyway - it's just a cultural thing maybe.