I admit to being puzzled by the 'skills for crafting' thing... I think of my PC's as fictional characters that I'm both writing and performing --at a nerdy dinner theater that bears a curious resemblance to my living room-- and as such, having mechanics that represent their ability to farm or blow glass have nothing to do with the real business of characterization; creating a personality, motivations, mannerisms, etc.
Looking at it that way, you can only prioritize what's included in the system. Seeing as there are so many potential interests and areas of knowledge/expertise for an RPG character, I prefer that the system only concern itself with the most relevant --to the genre(s) at hand-- skills and abilities, leaving any further description of character outside the purview of the rules.
Of course. But a player could just as easily tell the DM/GM that their character is into haiku and would like them to factor into the campaign. In other words, if a given skill is really just a marker of interest, why does it need to be part of the skill/task resolution system?
An example: my 4e paladin is a poet. There is no way (exact) way to represent this in the system. It's no big deal. The DM will use Diplomacy checks and straight WIS/CHR checks when necessary. The DM knows that aspect of the character is important, because I've told him it is, and I play in up during the session. Having rules for poetry writing and performance won't help me further characterize my poet PC (for that I'll have to write some real doggerel, or, more likely, parody some famous poems), and these rules, if they existed, would just clutter up the PHB (or some splatbook).
Why should a player have to choose between being an interesting character and a good (more effective) D&D character? The last thing I want to do as DM is impose a mechanical cost on characterization.