There might be more to the assertion that "BDSM
is the sign of a sick society" than meets the eye. Its advocates might really be saying "BDSM is the sign of a society in which Christianity
has lost control." This controversial sexual practice performs many of the functions that used to fall under Church
canon, and may (I'm not drawing any conclusions here, just presenting my ideas) be simply the secular
ization of instinctive human practices that were, for years, the province of religion.
Think about it. For centuries, churchgoers have been going to confession, asking for punishment from priests. A dominant in a Church-controlled society could (at least partially) satisfy his natural urges by becoming a man of the cloth, assigning penances of varying cruelty to believers in exchange for the forgiveness of their sins. If there was a stronger sexual component to his urges which the confessional couldn't satisfy - well, there were always plenty of altar boys around. The submissives thus had a predictable outlet available every Sunday for their control-surrendering impulses, as sure as the church bells tolled.
The principles of BDSM are, in many ways, an integral part of the Christian religion. Taken to their extreme, flagellant monks could inflict grievous wounds on their own bodies and believe themselves closer to heaven. Black-robed Inquisitors could take holy delight in torturing heretics on the rack and burning them at the stake. Next to these atrocities, voluntary dripping candle wax and lashes from a leather whip aren't just innocuous; they're downright progressive.
With BDSM's rise in popularity, the religious ecstasy associated with sadomasochistic practices has largely been replaced with that of the sexual variety. "Forgive me father" has, for many dominants and submissives, been supplanted by "whip me master." Dominance and submission can now exist in a community of voluntary association, their pleasurable aspects highlighted and destructive impacts minimized. These impulses are a part of many people's nature; their manifestation as BDSM may not be the sign of a sick society so much as a secular one in which the chains of the past don't carry the weight they once did.
Kinky sex has never precipitated genocide or inquisition. Don't waste your energy pointing fingers at this straw man - if you want to fix the problems of society, you've got to find their roots.