(I am male and going to be 27 in a month)
The age groups I have observed here (in Greece) are the 14-16 year old girls who dream of becomming a dancer (not necessarily knowing what they themselves think a dancer is, then again I wanted to be an architect and had no idea why).
The women over 40 who love dancing and are either single and don't want to stay alone at home or those that have realised that they don't need their husbands to dance and now that the kids are old enough to take care of themselves, have finaly found the time.
Then there is the ladies in their late thirties who are the mothers of the 14 year olds and who decided to tag along with their daughters.
There are also young women in the 18-20 range who have just started universtity and not yet felt the pressure of important exams, parents asking when they will finish and what happened to all the money we send for your studies.
I have the slight feeling that women who do not yet know how to dance are slightly intimidated by men who do.
I think that it has to do with young girls dreaming of dancing , older women having the courage of finally realising their dreams on their own, but women inbetween knowing that they are supposed to be the ones really wanting to dance with the guys saying "I don't know how to dance" but the men they meet in ballroom being to a large part more experienced or seeming to progress rather rapidly at first, if they were the same level, as those guys that stick with it are the ones that really love it.
A lot of the men I met that started dancing just to meet women stopped after a month.
I found though that these "predatory" men hennepin mentioned in her post were treated far better by many women than those of us who do not flirt with everything biped and female.
(the explanation female friends gave me was that with that type they know what they are while men who are just having a good time dancing and dont want to get them in bed are strange...)