I was born in the 1950s and I've never seen anyone like me, in any role, my entire life. I'm a heteroromantic asexual and how many, straight or queer, casn get their herads round that? Folk may be scared of, or disgisted by, homosexuality or bisexuality, but asexuality? *headshake* "Naaah! Everybody wants sex!"
I'm also a man from the North of England and you may search the media until your eyeballs fall out, but you will never find a positive or non-stereotypical representation of one of those!
They threw people like me a bone with Ecclestones' Doctor, but spoiled it from the off by making a joke of it -"Lots of planets have a North!" , then making him behave like a 'typical' Northerner most of the time (like being nearly-homophobic around Jack Harkness and going on about 'Mickey the Idiot'). They couldn't get their heads round a Northerner who wasn't Arkwright or Compo and that's why Ecclestone quit so quickly.
And no, Lt Uhura (she didn't get promoted until the films) wasn't a maid. She was the switchboard operator -hardly a step up, and still the lowest-ranking officer on the bridge except for Ensign Chekhov -who was a Russian. But Ms Winfreys' reaction shows how effective these con-jobs can be.