There is a “back story” to the jokes. The recorder versus whistle battle is not merely an issue of one instrument being better suited to a particular kind of music than another. Not that long ago, there was real hostility towards traditional music from society’s more “proper” quarters, and for many Irish the recorder was perceived as being as much an instrument of social agenda as much as of music. Writing in 1970, Breandan Breathnach in his “Folk Music and Dances of Ireland” pointedly described this situation:
"It is strange that one should have to appeal to a people to become acquainted with its own music, and that folk music should have to fight for a hearing against art music. Admittedly the bias of the urban musician against folk music is not a phenomenon peculiar to Ireland, but for historical reasons the division between the performer of art music and the traditional player runs much deeper here than in many other countries. “
“Institutes of music, whose activities centre largely on the preparation of pupils for examination, use tutors and texts which maintain a silent but effective boycott of the native music, and school authorities take something more than a musically decision in introducing the recorder and Elizabethan music into the classroom."
“The best way to acquire a real knowledge of our folk music is to learn how to play it, and the easiest way to make a start is by taking up the whistle, which is the easiest of all instruments to play. All forms of ornamentation in use rendering songs and dance music can be executed on it, and its costs only a few shillings.” (from pages 120-21)
History and jokes aside, the major issue that inhibits the recorder’s use in Irish music is style. Far too many recorder players render Irish music in the same fashion as they would William Byrd, Susato or Praetorius or any other piece of early classical music, not realizing that Irish music is a separate thing unto itself. For an approximate idea of how this sounds to a traditional musician, imagine African American gospel music being sung by a classically trained Wagner specialist. Rarely are the results musically convincing.
Don’t get me wrong, the recorder is a wonderful, versatile instrument in its own right. For long while I was involved in Early music, and still own a set of recorders. Occasionally, I’ll unearth one and give it a good workout. But I believe in using the right tools for the right jobs. It would be a gross understatement to say that I love the sitar. But hey, you wouldn’t want to hear Chopin on a sitar, would you??? 
All things considered, I feel the whistle and simple system flute are much better suited and more user friendly to traditional music. Yet surely it isn’t impossible to play all Irish music on recorder, certainly much of the older music (like O’Carolan’s compositions) can work nicely on recorder when played with consideration of style and period. Recorder players would do well to listen and learn from whistle and flute players. If you aren’t familiar with his work, Ireland’s Douglas Gunn is a recorder player worth checking out. In addition to several recordings, he has published many arrangements of early and traditional Irish music for recorder. His site:
http://www.melrosemusic.ie/dgunn.htm
