I think Profession skills are invaluable. I know we're in a fantasy setting (where does reality fit into fantasy), but realistically everyone knows how to do something. Wether its the one or two ranks you get watching your parents be farmers (or merchants, or whatever); or wether its the 5-10 ranks you have for being a blacksmith's apprentice before you went off adventuring. Everybody can do something.
And as a DM, I'll allow a player to use a profession skill check in place of something else - as longs as it fits the situation. For example, profession (merchant) when trying to haggle a price (instead of Diplomacy), etc etc. I'm glad they're there. Yea, they're mostly for roleplaying - but not always!