It sounds a little like the '50s crime comic books, where the gangster was treated like a hero for most of the book, then gunned down at the end to prove that "crime doesn't pay." But these books both end badly for the same reason, the assumption that a BDSM relationship has to go on getting harder and more extreme till it ends in the sub's mental or physical destruction. Another book with a similar theme, which might have been written as a feminist answer to "9 1/2" and which I'm definitely not recommending as a hot read, is "Nothing Natural" (Jenny Diski). In this the sub is presented as a seducer's victim from the start, and ends by turning the Dom in to the police. (Though the moral lesson is confused: she seems to be a completely split personality, one alter loving her Dom and the other plotting to destroy him, and what she turns him in for is a crude frame-up which in the real world wouldn't stand a day's investigation.)
Were these authors reflecting the fears society presented to them, that their abnormal tastes must end badly? A few decades earlier, mainstream stories of gay relationships always ended in tragedy, and again it's hard to know if the authors were writing what they felt would get published, or internalising society's distrust. Maybe the reason people aren't writing stories like that any more is that we simply have enough examples to prove that non-standard sexualities can live happily ever after.