The problems with mislabeled CATIV ratings apply only to a small number of people. If the meter does not blow up when connected to the mains outlet then most people are safe. If the meter does not blow up when connected inside the breaker panel of a flat (or individual house) then even more people are safe.
So, showing that a meter with the wrong rating can explode when connected inside a substation (especially if it's the 10kV part) will make most people go "well, I'll keep that in mind if I decide to break into a substation to steal the oil".
I don't agree.
Technically your statement is partly true (if you measuring only low level voltages, CAT ratings are not that important), but the whole point of measuring is to find out unknown value. If you already
know in advance about mains level, why do you measure it? It is because you don't
know what reading will show. And this is the problem - you are measuring
unknown voltage source while assuming that it
should be safe (which might not be true). Reasons for potential dangers were well explained in other posts.
My point is that in almost all cases where injuries occurred (or were close calls) person measuring the voltage
assumed (but did not
knew exactly) that both meter and voltage levels are safe for work. See posts above - "I thought it is OK", "it is only low voltage", "I have done it before", "I will show other guys how to do it", "meter looked good enough", etc. If one always goes with such logic, one day serious accident can occur.
The other point is a lie about CAT ratings. Would you like a lift with fake maximum capacity rating/plane with false max cargo weight/building with false load rating/etc.?