[tritogeneia]

I think this is more a matter of transferability. If you're good at one quantitative or technical skill, it's not so hard to learn another, and you can do it pretty quickly. Teaching yourself to become an artist is a bigger gap. I can appreciate design (although I never studied it formally) but I can recognize that it may be more efficient to get someone else to do it for me. The optimal degree of specialization isn't always "none."