Inevitably, people wind up rationalizing their own lifestyle and, at times, defending it, at the expense of alternatives. Oh, I don't think it's hopeless at all, if that's what you're saying. To me, that passage strikes at the heart of the whole book. Sex is free expression. It's a language we all speak.
Sexuality offers power.
Power leads to control. But revolutions, of any kind, are not popular with authority. Well, this is essentially the threat you pose to authority. Yeah, that's me. The status quo has always given me the creeps.