Some posters seem to take a special dislike to the spectator element:
"I dislike women "doing performance" - whereas other sorts of dance are more about participation and socialisation. I dislike women being things that are looked at and ballet seems to encourage this in a very ghastly way"
"But then i don't agree in general with parading children to be gawped at..."
So any acting is out then. Am-dram straight off the list. (is that both men and women or are men still allowed to present themselves to be seen?)
Also any spectator sports. (or are we seriously going to argue that the World Cup and Wimbledon are simply about participation and socialisation?)
Not sure how we stand with musical performances? Is it ok to be listened to but not looked at?
Not letting girls do ballet because only certain types can make it to top ballet schools or make a career of ballet seems about as sensible as banning little boys from playing football because most haven't got the physique to become professional footballers. Or not letting them have swimming lessons because of the pressures on Olympic swimmers.
Most ordinary ballet schools for young children (of either sex) are about participation and socialisation. The pressures of professional ballet are simply irrelevant, just like the life of a professional gymnast or footballer is not relevant to the little boy (or girl) who joins Tumbletots or fails to score a goal in the house match.
If we are talking about what happens at prestigious ballet schools, then we should be comparing with a similarly prestigious sports setting, not with the school football team or the local swimming baths. In both cases, we are talking of specific settings where future professionals are selected and trained. I am fairly sure that young potential Olympic athletes or aspiring footballers are also judged pretty harshly and discarded if not good enough. Or do you think the first concern of Olympic talent spotters is to be inclusive of all physical abilities?
Otoh my experience suggests that a bog standard ballet school is far less likely to chuck out a clumsy 10yo than e.g. most bog standard football teams for the same age group. My mildly disabled ds was never able to get into any football team, inside or outside school, though he would dearly have loved to join. He was de-selected, if you like, on his body type. The local ballet school were happy to have him, and were always keen to include his more severely disabled sister, even on days when she arrived in a wheelchair. They also included children with fairly severe learning difficulties who could never have made it into a mainstream sports team.
As for the dieting, does anyone really believe that professional athletes get where they are without paying attention to what they eat? But does that mean we should stop our children doing handstands down the park? Or not let them take part in the annual dance show (where the only dietary advice is likely to be "please don't rub chocolate on your costume")?
Dd was not particularly good at ballet. But it sparked a long-lasting interest in theatre and in using your body to tell stories. One result of this, as far as I can see, is that she has been far less interested than most other teens in worrying about her looks or about being conventionally pretty: to her her body is a tool and she is interested in what she can get it to do.