"I'm just chipping in to counter those calling it abuse."
Isn't that the kicker though? You are free to criticize particular sexual practises because you feel they are problematic/abusive/stupid, or just downright weird (like being sexually aroused by sherbet lemons say, due to a youthful fixation on Dumbledore........), even if those indulging in them are two (or more) consenting adults. But if someone gets to label a practise (or a group of practises, like BDSM) as an orientation (hence what a person is in some sense), then that is now out of bounds!
The difference between, say, thinking anal sex isn't the best thing ever, and using the same argument as a closeted attack on gay men, or just thinking gay men are unnatural because of the association between gay men and anal sex. Except there the false link was being made to disadvantage gay men.
I think that is what is being attempted here, and also if successful means that the BDSM people in question could make it a 'lifestyle' and a more public thing on the grounds that rather than being a private sexual practise, it is a 'sexual orientation', hence magically protected (just like gay people)............
Doesn't half piss me off though, the many groups trying to exploit successful campaigns for lesbian and gay rights. See, I'm of a generation when it was mostly L and even letting G in was problematic............