@WbS Granted times change but socialism liberalism as an intrinsic part of socialism is by no means solely a post-’68 phenomenon. Socialists in the 19th and early 20th century were the most extreme social liberals of their day: Engels’ on The Family, Private Property & the State, the Bolsheviks’ decriminalisation of homosexuality right after the revolution etc. etc.
The maximum, minimum programme quote is from Gramsci and was a widely held view among revolutionary socialists in the 19th and the 20th centuries. Authoritarians and reformists might have thought differently, but again I’ve yet to see a left wing argument for them – rather than an accommodation with conservative ideologies/political expedience.