I dont really want to be an apologist for the discriminating landlords of the 1960s, but in the face of so much right-on-ness I feel like pointing out a few things
The first is the nature of rented housing in those days. All those grand houses in the crescents of Notting Hill, all those smart Fulham terraces would, in those days, have been houses in multiple occupation. Tenants occupying one or more rooms, with minimal, if any, structural conversion to give them a self contained space behind their own front door.
Often sharing cooking facilities. And bathrooms - if they were lucky & there was one on a half landing. Otherwise it was a weekly trip to the Municipal Slipper Baths. Just check out the Census statistics &, if you can get hold of a copy, the Enumerators Instructions for the 1971 Census of England & Wales.
The landlord - often a widow - was quite likely to be sharing the house too.
Wouldnt you want some say over who lived with you in such hugger-mugger fashion?