Dictamnus Albus-- What you appears to be your issue is how your belief that beauty is inherent to femininity conflicts with the idea of female-to-male crossplaying, which isn't so much a sexist (at least to me) mentality but a rather rigid one. I take from your posts that you don't consider males beautiful so you aren't bothered by male-to-female crossplaying, but you think females are beautiful by nature so they risk making themselves ugly by "masculinizing" themselves when crossplaying. The solution to this problem may be if you try to separate attractiveness from gender altogether.
If beauty is attributed to solely individualistic traits and not directly to a person's gender identity (or biological sex, for that matter) then female-to-male crossplay will be less troubling. While you're obviously more attracted to feminine qualities (and that's fine), do you think masculinity as a whole is ugly? Is it impossible in your eyes for anyone of any gender to look good when they take on masculine characteristics? You mention other ways besides crossplay in which you think women intentionally make themselves ugly, but what's to keep things like facial piercings and ill-fitting clothes from having the same disfiguring effect on men? The connection you make between gender and appearances has caused you to create two sweeping and very restrictive generalizations: "females are always beautiful" and "males cannot be beautiful." This binary is what's skewing your perception of certain phenomena like crossplay. Separate beauty from gender and not according to gender, and an individual's attractiveness won't have to be affected by their gender expression at any given time. Now of course the question of whether or not said person looks good as that particular gender can still arise but at least there is no longer a need to fear that beauty will be automatically compromised in trying to achieve masculinity.
We can go even further and separate gender from identity (of either the cosplayer or the character they're portraying), but let's just stick with the topic of appearances for now. I know this wall of text may or may not persuade you into thinking any differently about crossplay but I at least want to say that as a non-male-who-cosplays-males myself I'm not offended by your posts and I think I understand your opinion.