i understand your position and i'm somewhere between the two ends, or should i say i agree with both argument.
sounds contradicting i know .... but that's my view for now.

i saw a documentary by national geographic channel on human brain which feature a boy with perfect pitch
http://video.google.com/videoplay?docid=-1955232874558919934it does mentioned that the human brain goes through 2 stages of cutting off connections that wasn't used (first few years of birth and at adolescence)
thus, it may does suggest that if you do not use your perfect pitch if you have it, you might lose it.
the reason i'm asking is i'm suspecting one of my kid is having perfect pitch but couldn't really confirm it.
and if he does really have perfect pitch, i would like to know what i can do to help him to keep it.
looking forward to any advice.