1. An interest in spanking is far less socially acceptable than being gay, and spankos are not open about their interest.
So... for all those ladies that swoon at the idea of a Don Draper type rolling up his sleeves and taking them over his knee... maybe he goes to see a domme to let loose (and does nothing more than fall to his knees after chasing and catching his wife-- tell me someone else saw that episode.) Meanwhile that small obnoxious IT guy with self-esteem problems has not just one, but a harem of collared slaves he found on FetLife. And that cute girl at the office who's always volunteering, always bringing cookies, and remembers everyone's birthday... maybe she asserts herself at home, taking out her pent-up frustrations on her husband's ass. Now stereotypes became stereotypes for a reason, and there are certainly some dominant Don Draper types that are into being the head of their household and spanking women. There are plenty of alpha-male spankers and plenty of submissive ladies that like to have their bottom warmed, and dominant women that like to spank and men that just naturally like to serve a strong woman. But that's not always the case. And because that's not always the case, a spankdar is practically worthless.