There used to be a PINK AIC
Which said "as of 14th November 1989" (or 1988 I think) "All pressure settings will be in Hectopascals"
But nobody read it....
At least hPa have 'meaning', enabling pilots to understand that Standard Pressure is 101,325 Newtons/Square Meter
Since the strength of Earth gravity is about 10 Newtons per Kilogram you can see that Standard Pressure is like having 10,000 Kilos per Square Meter .... or 10Tons per Square Meter.
1hPa = 10Kilos per Square Meter
(approximately)
Link:
www.caa.co.uk/docs/33/IN201143.pdf