Freddy,

That is a good list list of programmes but spread over more than one radio station.
Some of these e.g.
The Orkney and Shetland programmes are only broadcast regionally on their own local BBC radio or Radio Scotland in that particular area.

Some of the programmes are on Nan Gàidheal which is available on FM and DAB but not AM in most areas.

Of course, it's easy to listen live or again on BBC Sounds these days but not everyone finds it that convenient. Casual listeners won't always bother and will just listen to whatever hapepns to be on at the time.

Having said all that, your point about Scotland being well served compared to other parts of The UK is valid. Also, there's nothing to stop the rest of The UK, Ireland, and beyond from checking out these programmes either and enjoying our Scottish music.