who knicknamed the bbc aunty ?

[nemesis]

I'm aged 70 and 'Auntie BBC' has been a sort of affectionate term used for as long back as I can remember.
Most take it to mean 'prim and proper' - a tad old-fashioned - reflecting the somewhat patronising way programmes were originally broadcast.
The BBC's Charter specifies the main aims as being - to inform, to educate - and to entertain, with the latter originally rather more 'refined' than what we get nowadays.
The introduction of ITV/Commericial TV was seen by many as 'lowering standards' - especially with 'game shows' for Joe Public winning big prizes before squealing, easily excitable audiences.
Audience ratings made Auntie raise her skirts to match, especially in the Swinging 60s - when satirical programmes challenged 'old-fashioned' attitudes, such as respect for authority, politicians, religion, the monarchy etc.- and the sexual revolution loosened the restrictions on what was deemed 'suitable' to be broadcast.
Some believe that politically, the Beeb has become anti-establishment, rather left-wing, but then the Lefties argue the opposite - so one can assume Auntie has the balance just about right.