In the 70s and 80s BBC Radio 3 used to broadcast a regular half hour, repeated later in the week, which somehow I never got to hear when it would have been helpful, e.g. in my teens, though latterly I did tape a great many. That stopped and the instrument was told to hold its own and not have a specialised niche, which meant it largely disappeared, with very occasional notable exceptions, including Sean Shibe.
Classic FM, which has been discussed above and well as on another thread does actually play quite a lot of some players, with whom they have commercial arrangements to some extent.
Is it possible your local station has employed a particular individual with experience of guitar? A lot of times its not the presenter who makes the choice, but producers and other controllers in the background. You could even ask them and encourage them to do more, stations esp local ones often like that kind of feedback.
I played my baroque guitar on a very small local station a while ago, I suspect the audience was in single figures. Made it low stress!
Simon Ambridge Series 40 (2005)
Trevor Semple Series 88 (1992)
Louis Panormo (1838)
Alexander Batov Baroque Guitar (2013)