To confine your repertoire to 'English' songs (whatever that means) is odd, to say the least.

True, but there's a difference between "English performers should do more English material" and "English performers should only do English material". I think the first of these is quite a reasonable statement; I don't believe Richard is saying the second.

But there's a bigger point here which is genuinely political. Ireland, Scotland and England have all got many different regional traditions; nobody would say that there's a single tradition that includes Buttered Peas and Elsie Marley, Come Write Me Down and Ee By Gum But I'm Cowd. In the case of Ireland and Scotland, what makes it reasonable to overlook those differences and talk about 'Irish' or 'Scottish' traditional music is the history of the country: what unites the Scottish traditions is that they're music of the people of Scotland, a country that's been ruled by England for the last 300 years.

England's been its own boss since 1066; English nationalism has an army and a navy. Unlike Scotland and Ireland, there's no theme of rebellious popular nationalism that can tie all the different English musics together. (I believe this is the kind of unifying theme that the more radical Revivalists were looking for, particularly in the quest for industrial folk song.) I think you could say you were into West Country folk song, Lancashire folk song or Northumbrian folk song without anyone batting an eyelid; English folk song just sounds a bit, well, patriotic.