We have two uillean pipers in our sessions who apparently have no problem with tuning nor in playing with others. There is the occasional technical issue, but nothing more disturbing than a broken string. No noodling - when they start, they really play; everything else would be inconsiderate at that volume. Role models of discipline.
To return to the original question: What's the deal? The piper gets expectation and respect for playing the most difficult and most irish-sounding instrument of the pack, and in return does his best to fit in with the others.