Perks work AGAINST both those aspects. Perks force typical players who would otherwise be happy consumers into being producers themselves in order to get those perks, which will (eventually) be deemed neccessary to "compete". Thus both reducing demand (less people needing/wanting to buy your products) and increasing supply (more people able to make said products). Thus any particular crafters "share" of the population dramatically decreases. So less people buying a particular persons stuff, and using a particular persons stuff.
I'm also not talking about money-making in this. I'm talking about just the skills themselves. If there are no real perks to crafting, then what's the point to having any crafting skills? There aren't any incentives. Is there anything other than money? Because I don't really see it. this is going to sound snobby, but it's not meant to be. I always thought crafting shouldn't just be about the money, it should also be about customizing your character.