Clarifying IP Metaphors

Jonathan Peterson weighs in at on the debate about intellectual property, copyright, and source code pinging around the blogosphere these days:

I think Doc’s tendency to not pour any more legal epoxy on top of the sand foundation of our software intellectual property is a good idea. Technical solutions and protections are one possible solution, a complete rethinking of software intellectual property, based not on patent or copyright, but something in-between would be even better. Dave’s flip response comparing traditional property rights to software is a bad metaphor, one that over-simplfies some of the deeper thinking Dave has done on the subject.

OK, but don’t just say it’s a bad metaphor. If it’s a bad metaphor, why is it bad? How is a house not like an intellectual creation? I think some of Jonathan’s earlier comments in the same entry comparing blueprints to actually built houses shed some light on this line of thought, but I still think he needs to go beyond the raw assertion that the metaphor doesn’t work. Tell us why.