Sorry about the length of this post.
Sakura, it is not that have not thrown aside my argument; you argued with me on previous threads and I changed my mind because of it. I agree with you that female things should be celebrated. I see this as one of the most positive things that has happened to me on MN and has given me a totally different and more ethical perspective on many issues. I have a much better understanding of how women are damned if they do and damned if they don't in terms of a number of issues of behaviour, such as stereotyping of SAHMs but also things like what makes a credible rape victim.
But that still leaves the thorny issue of things that are not inherently female but are traditionally feminine. While men may have determined what is feminine and what is masculine, once pushed into those feminine categories, women have put much energy into those cultural traditions. So women have put much creative effort into developing things like cheerleading and we shouldn't be dismissing it simply because it is sterotypically feminine (which is not to say that there aren't other issues with it, as you have pointed out). We shouldn't dismiss it as being on the sidelines, rather we should respect the efforts of all the participants who have taken it away from the sidelines and made it into a sport that they compete in at entirely separate events that have nothing to do with football or basketball or whatever.
But to put the whole issue of cheerleading to one side for a moment, because I think it is secondary to the more interesting discussion of feminine (as opposed to female) activities, we could look at something less problematic such as knitting. Knitting is sterotypically female, and as such we may not want to push girls into doing it and boys into not doing it, because we don't want girls or boys to be confined to solely doing gender specific activities.
But that doesn't mean that we should make out that knitting is somehow a lesser activity than say carpentry. And I think that feminine activities are denigrated by society, and as feminists we have to consider the merits and the pitfalls of feminine activities.
There are parts of activities done by women that have such negative connotations (lap dancing for example) that I would like to see them disappear, regardless of the efforts women have put into developing them.
There are other activities done by women that have both negative and positive connotations ( and I think cheerleading is such a case) where I don't think we should dismiss the positive efforts women have made, but I also think we should acknowledge the negative elements.
There are then activities women have done (knitting for example) which I would would consider wholly positive, but only if the acknowledgement of them as female developed traditions is understood in the context of women no longer being constrained by an expectation of them only doing the specifically feminine.
But the problem seems to be that a great many of our traditions do involve a mixture of positive and negative elements, and it is how we then deal with those traditions. And I don't know what the answer to that is. If it was simply a question of cheerleading I wouldn't be concerned, because we would just tell our daughters not to cheerlead, but negative masculine and feminine stereotypes and behaviours are threaded through so much of our culture that I don't see how we can throw out all of those activities - we have to find ways of changing them instead. These stereotypes are everywhere - if we got rid of all the problematic children's literature (for example), there would be almost nothing for children to read.
I think the problem you are bringing up is central - the idea of women being on the sidelines. But when women drop feminine activities and join men's activities, they are still then on the sidelines in a sense (certainly in terms of numbers, which alters the culture). One of the great things about having young children is that you can enter into a culture of women, but many women will spend a lot of their life not bringing up children. Whole sections of my life would fail the Bechdel test, and I think it is that which draws many girls into feminine activities.
So perhaps one possibility is that rather than prioritising masculine activities (where they will struggle to experience equality into a patriarchal society), we acknowledge that there are self-esteem benefits to girls sometimes doing feminine activities where girls traditionally dominate and can bond with each other in a sub-culture where most participants are girls. Although obviously there are feminine traditions that are less problematic than cheerleading.