Yes, it was the general attitude at the time."Sex" was something dissolute, and even if you did IT it was not something to boast about in decent compnay.
BTW, the real quote was "There's no sex in USSR... on TV" as you probably know.
Hmm.."Рок-" is not an adjective. I'm not sure what it is. "Онлайн" is often used as an adverb, and it can be used as an adjective too.. Though some people say "онлайновый" in this case.Also as for indeclinable adjectives, I just thought of a couple of other ones... рок- as in рок-музыка, and онлайн.
It seems poor Russian language has no idea what to do with all these weird words that assault it in the recent years. many Russians are confused too. )