A recent and insightful Computer article from Stephen Jenkins (Concerning Interruptions) led me to rethink my authoritative position on working with headsets (read Kindly Kill That Headset).
I think the crux of the problem is not about knowing if programmers need isolation to avoid frustrating and concentration killing interruptions (this is granted), but actually respecting this need for isolation.
If everybody would respect this need by refraining from asking out-of-context questions (the most brain resources consuming ones) and by saving interruptions for better times (like planned meetings, lunch time or pit stops), programmers would need less to stick headsets on their ears and would therefore be more available for direct in-context questions from fellow team members.
Aretha was right: it's all about respect!