The problem here is that we have taken something one does (crossdressing) and and turned it into something one is (a crossdresser). We talk not about 'crossdressing' the activity, but about dentifying ourselves - and others - as 'a crossdresser'. No longer a means to an end, crossdressing has become the end in itself.
There are many reasons why someone might crossdress. That single activity, however, is not the sum total of what someone is. Technically, if a woman puts on a pair of men's boxers or BWBs, one could say she is 'crossdressing' - we would not, however, consider her a 'crossdresser'. If a man wears a blouse simply because he likes the colors, he is 'crossdressing' but not necessarily a 'crossdresser'. Why is that?
And yet, if one of us puts on a pair of panties, we are a 'crossdresser'. Why? What is it that makes the distinction?
It is the intent behind the action that makes the difference. As a rule, we do what we do not for comfort, practicality, or even sartorial creativity. We have an agenda, a purpose. We crossdress to present ourselves as women - or to express what we like to call our 'feminine' side - or simply because whatever we want to call ourselves, crossdressing allows us to express that.
Rather than say, for example, "I'm transgendered and I crossdress as a way to express that aspect of my persona." - we will say "I'm a crossdresser." The implication here being that the signifier 'crossdresser' carries with a set of culturally defines assumptions - much as 'man & 'woman' do - applicable only to a specific group of individuals - those gendered at birth as 'men' but who present themselves in a way traditionally associated with women. It is for this reason that women 'crossdressing' are not 'crossdressers'. It is not an appropriate label as it incorrectly signifies menbership in a group to which they do not belong.
Of course, this all works the same (in reverse kinda-sorta) for our F2M brothers.
In the end, it had very little to do with the actual clothes and everything to do with the message one trying to send.
Love & Stuff,
Donna