There have been a couple of female chat show hosts:
Trisha, Caroline Aherne/Mrs Merton
But you're right, MASSIVELY outnumbered by male hosts.
As for female newscasters, where I worked, the main TV news anchor had straight blonde hair (!) but still lost her contract after several years of enduring popularity because the management (I have good reason to believe) had decided she was getting too old (yup, ageism is awful when it comes to female tv presenters) and too expensive (she had a good agent).
Certainly, the female presenter/s that replaced her were all younger and cheaper....
It's bollocks, the lot of it. Pah.