Been resisting but can do so no longer - just had to join in.
I believe that the distinction that has been alluded to is that a WO, particularly an ex-ac tradesman, will have taken approx 25-30 years to attain his rank. Hard fought years gaining massive experience as a Junior airman, JNCO and then graduating through the SNCO cadre.
Not that I am inferring any less honour to the MACRs but anyone who has been a MACR for 20 years - and still serving - is either 80 years old or was promoted to MACR after approx 10-12 years service.