The structures are never completed products, since you want them to last, to evolve along with their applications, to be friendly to new apps. A complete website redesign has no equivalent in a good application information structure. So of course I'm particularly aware of all of them, and there's some translation that has to happen between each, but the idea is either to minimize that or to make it seamless and scalable. Don't want to disappoint you as a would-be uniter, but I bet very few people are good at both. And there's less room for speculation and rambling theorizing, which is definitely the fun and social part.
Musicians organize sound.
Writers organize thoughts. Software architects organize application logic. I'm sitting here trying to organize variants of information architecture. But the fields are pretty divergent and that's why we usually specialize in just one. An architect I know thought it must refer to the person who kept track of the specs for buildings.