The point I am making is that the Irish people have proven themselves more than capable songmakers - why not the British?

Both were even better at forgetting songs that didn't serve a long-term function than they were at creating them. Whereas the at-some-time-print-transmitted stuff had staying power.

I heard quite a few chants at the Edinburgh "Dump Trump" march last weekend that were entirely new to me. How many am I ever going to hear again? Not a lot. I can think of only two chants of that type that have lasted decades ("the people united will never be defeated" and "Maggie, Maggie, Maggie, out out out!"). Ephemeral creation is ubiquitous. Roud's interests seem to be mainly in songs that persist long enough to be traceable.