It troubles me to see so many in this thread that are keen to have the discretion to disregard the GPWS. Whilst I agree that experience helps a pilot make sound judgments it certainly doesn't necessarily guarantee the best result.
If experience were adequate to ensure the correct outcome in these situations then why are the hillsides of the world littered with the remains of experienced crew and their aircraft? (Some of them even died in daytime VMC!)
I expect that if you could ask the crews of those aircraft which flew into terrain whether they thought that they knew where they were and what they were doing prior to impact, then some of them would say that they did. CVR analysis shows that on most of them at least one crew member was uneasy (often the subordinate).
Experience unquestionably helps a pilot to make good judgments, but a little humility goes a long way to helping you stay alive.
GPWS came in to help pilots that think they know what they are doing realise that they don't!
Nobody is THAT good a pilot.