Interesting comments, GUEST, and although I've not seen RTB yet, I can fully understand what you mean, not with him, but other artists I've seen.

There seem to be quite a few artists around who write all their own material, and I'm impressed with this because I don't do this (or probably, can't). This sometimes does make for a lack of variety in the songs and style of presentation, leading to potential boredom for the audience. As you say, it would be better if some artists included more covers, to provide a bit of variety for the audience. Maybe these people take pride in not covering other people's songs, or something? Or maybe they need more honest feedback from people who care about them.

Me, I'm the opposite, because I don't write songs myself (or at least, not enough to fill a set) and I pinch songs I like from a variety of sources, ranging from traditional songs to songs written very recently. The only criteria are that I like the song and feel it would suit my style, and that I can actually sing it. I'm the opposite extreme to the likes of RTB (as described by GUEST), and I would like to be able to write more of my own songs to include with the ones I've nicked from other folk. They are in the enviable position of being able to do what I would do if I was able, so why don't they?

Before I get jumped on by "Mysterious starter of thread" and other RTB fans, remember I'm not talking about him as I haven't yet seen him. But there are plenty of other singers who fit the profile given by GUEST above.