Nor Divine, for that matter. Although generally known by his stage alias, Harris Glenn Milstead knew he was a 'he' and referred to himself as such. He became mainstream, and was a skilled, versatile performer with many facets.
McKellen is a wonderful actor. The ugly sisters in panto have also always been played by men. There's a lot of camp in theatre, and a lot is also funny.
I'm old enough to remember those truly dated, horrible comedy duos of which the Two Ronnies were one, and they often performed in drag. I clearly remember their fake mini-series starring Diana Dors called 'The Worm that Turned', where all men were forced into drag and called by women's names, whilst women ruled the world with a hard iron fist and turned the UK into a feminist dystopia. Their 'secret police' who marched around wearing shiny hot pants were memorable.
Barker was a genius. Even he couldn't have known at the time how precient his parody was - but the whole piece was a clear satire of the horribly sexist practices and attitudes embraced by the BBC of the day. This series showed what it might look like if the boot were on the other foot, and it wasn't pretty.
Yes, so the hot pants were terrible (!) and Dors screams when she sees a mouse, but aside from that I'd be inclined to view the whole thing as a very feminist commentary. It was clever stuff - dated but bitingly, wittily funny.
It also features a girl called Jack ...