Starting to trudge into this world myself, and I can definitely understand why there isn't a big rush of hackers into the production of physical goods. There are heaps of boring details to manage, supply issues to research, domain knowledge to learn, etc.

There is nothing intrinsically difficult about creating physical products, but you can liken to working with a very un-expressive programming language. You're spending a lot of time making very little progress, and it's very expensive to create prototypes as you go.

So it's slow. You don't get the same continual ego boost of seeing what you are building. And you can't hack it up over the weekend to the applause of your peers.

I am fascinated by the promise of 3D printing/manufacturing, but have yet to find a good use to justify the much higher cost.