"Part of their kink is adhering to a set of rules set by, smiled upon by and witnessed to by a community.
Having their behaviour normalised and validated by wider society is core to their kink. "
This rang a bell for me. It's the difference between having a single Person X who likes to do Y, and being part of a community/group, however large or small, that has rules and regulations, however formal or informal. It legitimizes it. Both for those currently in the group, and for those outside it. The in-group specialized language plays a dual role, in that if you're in you know what the phrases mean, but the phrases chosen also seek to make things sound innocuous. Breath play, the repeated use of play itself, the linkage of what most of us think of as childhood 'not real' let's pretend, with very real adult physical acts. Goddess, doesn't that in itself tell us a whole load about what is actually going on here!
Forget the 'play', let's get back to the normalisation that means that women are being expected to engage in and enjoy ever more sadistic and formerly niche sexual interests. Even at the heights of the lesbian sex wars, I don't recall the actual abuse or erosion of womens boundaries that seems to be happening now, just (at worst) mockery if you were boringly vanilla.
"Kink' just sounds a bit light-as-a-feather for what is actually being talked about here." Hiding behind the words, it's not actual pain or abuse or wounds or bleeding or fire or cutting, it's just 'play'. (some of the things I used to come across in discussions about lesbian S&M BTW).
And it's still as disconcerting as I used to find it 20-30 years ago. That's not because I'm not educated enough, or haven't met the right participant to explain it to me properly, or it isn't just because it's not what I'm into -- the basic concept here, as someone else said, it's not coming from a healthy place or a good place in our psyche.