I have a lot of reasons for doing it, but my primary explanation is that I was a gender illusionist for a while, but there wasn't a lot of demand for the characters I wanted to portray (which are mainly anime, cartoon, and game characters). Most performers in that field prefer Cher, Madonna, Lady Gaga. All of which are perfectly fine, but it just doesn't pique my interest quite like cosplay does.
That and I consider myself bigender. I'm completely comfortable in one gender or the other, and crossplay has always been a niche group in the cosplay scene. So I figured it'd be fun to try to expand it more, really get the word out that crossplaying is a fun hobby that requires a lot of skill.