It has nothing to do with altruism and everything to do with the fact that most people are not driven by the hoarding of wealth. Most people recognize the need to make a profit because they need to survive and support their families, but it is not their primary motivator. If it were, there'd be millions more entrepreneurs than there are, and few people willing to work endless factory or desk jobs. For most people, they are primarily motivated to do things they enjoy doing. For the sorts of crafts people I'm talking about, those things are engaging in their craft.

Altruism has nothing to do with it. Although, psychological research has shown that economics has it wrong: most people are basically altruistic, not basically selfish. It's how we can be such a social species. But that's a different discussion for another time.