no one is criticising his playing or his singing, however it is clearly a misinformed statement.
dave the gnome, what have your tastes got to do with this.
of course some scottish music, some irish reels for example are in the irish repertoire, and are adaptions of scottish tunes. miss mcleods reel, the musical priest etc.
music is international and crosses borders, your prefernces are irrelevant, the csharp d box and d dsharp systems have been shown to be not as limted as some people have stated with misinformed comments [that includes john kirkpatrick]
Music is imo about how it is played. NOT THE NATIONALITY OF THE PLAYER. although style is of course due to influences, but in 2021 we have access to international influences.