I play the harmonica too,in fact I am a Munster champion,and yes you were being patronising.
I repeat there is nothing particularly special about irish music,it is music, it uses a lot of the same modes as a lot of other western traditional music[scottish english american french german],some of it is suited to chordal backing some of it is more suited to dyad[two note power chords].
michael is a prat of the highest order,furthermore melody is something that is of importance to all traditiuonal melody not just irish,but that does not mean that chording on the harmonica is always inappropriate.