I think it's aimed at English people who think Unionism is a problem to be solved (or "cured"), and the author and editors seem to have forgotten--or decided to ignore--the existence of Scotland and Wales.

Similarly, I wonder whether the group surveyed in the cited poll was just people in England; all of the UK; or specifically England, Scotland, and Wales. Someone clearly decided to lump "I would like Northern Ireland to leave the UK and join the Irish Republic" with the "no opinion" group, but who? Was that the original poll (yes/no on being in favor of Northern Ireland leaving), or did someone decide to combine the "no opinion" and "I'd be happy either way" groups after the poll was finished?