Everything is a conspiracy to some people.
I can't understand what gripe you have with the ladies you mentioned, all of whom have fairly bright cheerful dispositions. The fact they are all gay is not something any of them make a big song and dance over (not compared to Sandi Toksvig or Susan Calman, both of whom I actually quite like (Toksvig especially)).
As for Ranganathan and Kumar (the latter I can't abide), they just happen to be in that group of comedians that seem to be getting a lot of exposure right one. You could just as easily had mentioned Josh Widdicombe, Aislyne Bea, Jon Richardson, Roisin Conarty, Jimmy Carr...