Halloween is big for Crossdressers and in the closet transgender people because it's a way to express themselves without raising an eyebrow or two (although the stealth trans will see someone crossdressed for Halloween and smile...knowing they probably just didn't wear it cuz it's halloween

).
The only time I dressed as a girl during halloween before I went fulltime was in 4th grade. It was more of a pet project for my step mother than it was for me.
I wore it for about an hour before the Halloween party. When my best friend did not recognize me, I immediately went into the bathroom and tore it all off lol.
I was a zombie that night and had a helluva time! So even when I knew I was transgender, I had no desire to dress. I think it was a mixture of "I don't want anyone to see how much fun i'm having as a girl" and it was a part of Maryland that just did not have a high tolerance for LGBT people...back in the 80s.
But I can see why a lot of CDs and Inthecloset Trans would take advantage of it. I just never felt the need to...but that was just me