...It's fifty per cent about listening and fifty percent about your playing skill.

Which also applies to any instrument. It's about being aware of what's going on round you and playing in such a way as to fit in. Both whistle and [descant] recorder can jar in a session because of their pitch, especially above 2nd octave G. Played loud they cut through the sound and both whistle and recorder will blow sharp if you blow even a little bit too hard which compounds the problems. Cheap whistles can be reasonably in tune in the first octave but have intonation problems above 2nd octave G which can be all but impossible to correct except by the very best players as these are inherent in the simple bore shape. OTOH the better plastic descant recorders have good intonation across the range but because they are "not whistles" tend to get blamed for the faults of the cheap whistles which most people come along with.

Instruments that have such stentorian voices simply don't mix with the flawed humanity represented by fiddles, flutes and whistles. Not to speak of harmonicas.

Far too often people don't bother to tune up properly in sessions so the problems of intonation are compounded.

Interestingly I have not met the anti-recorder prejudice among actual Irish people. When I have used my recorder in flute/whistle workshops the reaction has more often been one of interest and a discussion of the differences and how to make the most of the instrument in playing traditional music.

I must admit I nearly always play tenor recorder these days and I mostly play English music. Mind, English sessions often involve a very eclectic mix of tunes.