The storylines of most TV shows revolve around one of two aspects of the lives of the main characters. The first is their job and the second is their relationships with the other characters. Such things as their personal interests or idiosynchracies sometimes get mentioned, but it is mostly filler, smalltalk or referenced in conversations. It usually provides some of the humour or supplies some background to explain what is happening in the primary storyline. Crossdressing is usually too complex an issue to use as such a filler,and could possibly overpower the primary story, if it involves one of the main characters, because of the needed visual aspect of it. Homosexuality is now somewhat prevalent on many shows because it ties into one of the primary issues more easily, which is the relationship between the primary characters. Also, homosexuals represent a larger percentage of the population than crossdressers and their inclusion seems more logical.
Soap operas provided an ideal medium for the portrayal of crossdressing, as the story lines are ongoing for weeks on end, and the entire story does not have to be told in a half hour or hour segment as with most shows. I never saw the "All My Children" episodes mentioned, nor did I manage to catch the "Bunny" character on the old "Santa Barbara" show, because by the time I heard about it and began to tape the show, he had stopped dressing for a reason that I didn't hear explained. There was just a few references to what he used to do.
The British soap "Coronation Street" has had an ongoing MtF transexual for many years, but the part is played by a woman, and the character was not on the show prior to the transition. Unfortunaytely, soaps are going the way of the dodo.
Drew Carey's brother Steve was one of the best examples of a crossdressing character because he was ongoing for several seasons, appeared in either male or female mode for no obvious reason either way, was not one of the principal characters and was less quirky than the main characters. Despite some humour to his part, his was the most "normal" character in many ways. Also, near the end of the show he went into denial in order to marry Mimi, who was more of a "clown" than Steve ever was.