Crossdressers have always historically had a presence on alt.fashion, although it is likely that many are lurkers rather than active participants. One reason there is low posting activity from this demographic is that much of alt.fashion consists of ongoing threads such as "what color are your nails today?" which, while entertaining to the regulars who keep these threads alive for unbelievably long periods, are likely to make it more difficult for the crossdresser who is reading the newsgroup in hopes of finding useful information on fashion. These ongoing threads also contribute to a very high level of posts -- typically in excess of 200 posts per day -- which the crossdressing culture must sift through to find the posts that they *might* be interested in.
Add to this the fact that crossdressers frequently seek out information on breast forms, gaffs, wigs, and other articles of clothing not part of the usual topics of discussion in alt.fashion and it becomes obvious that this culture can benefit from a more specialized newsgroup, placed logically below the existing newsgroup as a third-level specialized focus.
Although many might believe that discussions of this nature belong in the existing alt.transgendered newsgroup (and its "legitimate" sister newsgroup soc.support.transgendered), the reality is that these two newsgroups tend to focus on the philosophies, motivations, politics, and other "weighty" issues surrounding both crossdressing and transsexualism; the introduction of threads on fashion and makeup tend to be quickly flamed as "trivial".