My guess would be that Unix chose many of its special characters and keyboard shortcuts precisely because they were easy to type on a US keyboard.
When I need to type Spanish characters like áéíóú, ñ, etc. I switch to latin american ISO layout using WIN + Spacebar and then switch back.
I have a strange ISO/ANSI US keyboard, with an ANSI left shift and an ISO enter key.
Trying to remember more than two layouts becomes confusing very fast. AZERTY and QWERZ are the two worst ones, fortunately I never need to use those.
These keys are present on the UK keyboard, but not the US: £¬
Compared to every other common ISO keyboard layout, ISO UK and ANSI are very similar. For non-programmers, ", @ and (nowadays) # are the ones that matter. For a programmer used to an ISO keyboard, the UK layout may well be a better choice than the US ANSI one. (US ISO would be a good choice, but the extra key seems to duplicate symbols already present on the layout).
I know you can configure that in IJ but I'm too lazy to do that, especially if there are many keys to remap.
So now I have a keyboard with UK Layout.
This is my #1 annoyance with German keyboards as someone who learned a UK layout and who needs to do lots of programming and terminal hacking (#2 is the swapping of Y and Z). I take it this layout was invented before Unix and its heavy use of forward slashes, but it does show how shortcuts are rather discriminatory. I know more than a few Germans who use UK or US keyboards because they dislike this unhappy feature.