I would have thought that the above statement was a bit much coming from someone who plays Irish tunes on the English concertina, for which there is - I believe - very little precedent in the Irish tradition, whereas the Anglo-German concertina is ubiquitous, particularly in County Clare

The English concertina and the Anglo-German Concertina share the same name but call for radically different approaches on the part of the player.

This is not to say that Irish tunes cannot be played on the English concertina. Indeed, the person who posted makes quite a good fist of doing so.

The thing about the tradition is that it changes. Within living memory there were no banjos in Irish music. Now look at the situation.