The exact reasons are unclear, however they will be based more in hearsay and conjecture rather than actual scientific evidence.
Another example of items in BS7671 which should have been removed long ago.
Yes and no really on that comment (I agree with the rest of your post though).
I reckon that 1/ it is a good idea to keep bog standard plugs and sockets out of the splash area such as baths, sinks and basins - although there is no actual reg measure for kitchens because it would make life impossible for some in the UK. I reckon with the 3m then 2.5 m it was and attempt to remove the complete ban of sockets in bathrooms (or rooms containing a fixed bath or shower) in order to avoid encouraging hairdryers etc being used near the bath.shower . Of course some folk will still do daft things no matter what obstacles you put in the way. The UK bathroom shaver socket does go some way to reduce risks but some folks still do daft things regardless.
I`m sure that some of you, like me, will have seen a bog standard 13A socket in a bathroom with shaver adaptor plugs in in order to use shavers and toothbrushes etc because it is cheaper and can be unplugged to use the hairdryer which is often directly over the basin too.
You can`t win.
If you say none allowed, some folk will ignore it, if you say 3m or 2.5m some will ignore it or reduce it, deliberately or carelessly - remember covid and the UK 2, rule? commonly known as 6 foot, well nearer 6ft 7in really but folks said 6ft then "misjudged" it to make it 5ft or 4ft or 3ft etc. You just cant win whatever you try.
Still with the covid 2m example, two things I saw stand out 1/ a shop where queuing was marked out by squares and included a 90 degrees change of direction, squares marked out on floor "2m apart" - that was to sq centres not square boundaries but the best thing was at the 90 degree change there was one square then a 1 m turn then 1m then next square so the resultant hypotenuse was not 2m but merely 1.414m anyway! 2/ Some benches, each with a large notice attached "2M and two opposing arrows" suggesting sitting one person at each end of the bench but the problem was that even if two people brought their own chair with them and placed them external to each end of the bench then it would still not achieve 2m separation (one saving grace that unless they turned to speak to each other their breathes were not directed at each other).
If people perceive an inbuilt safety factor in such rules and dimensions then they tend to reduce/adjust it themselves in practice.
Example, how high you are allowed to build a fence, marked lines for parked cars, current ratings of cables etc etc
So I think that the 2.5m or 3,0m rules were basically a good idea but folks still abusive them all of the time, like slavishly sticking to a rule as written rather than intended meaning - probably one reason why rules and regulations (including BS7671) are difficult to write.
