When I first started in IT - back when dinosaurs where roaming the Earth - the only people who used k were IT peopleAssuming that you mean 1000, rather than 100, the answer is easy - Windows calculates kilobytes as 1024 bytes, Mac OS as 1000 bytes.
and it was used to show how much memory a computer had - and it meant 1024 because it was always a power of 2
unless it was measuring print lines per minute/second - in which case it meant 1000
so that was clear
at the time if you meant kilometres - you used km etc etc
I find it rather annoying when a technical term starts to get used outside its original sphere - and its meaning changes
then its meaning inside the original sphere become ambiguous - where the point in using it was to be clear
Hacking comes to mind as well - hacking is hacking - a kid reading instruction on a cheat sheet is not hacking!!!!!!
nor is anything labelled as a 'lifestyle hack'