I'm not sure your assumption is accurate. In part because people generally don't study architecture at university, have careers in architecture, and do apprenticeships when talking about software architecture (and there's hardware architecture too, though the same applies though perhaps slightly less so). But all these are common when talking about architecture in the built environment.
The other reason I'd question your assumption is I'm an architect of the type that designs buildings. Though I don't practice much these days, I still keep one active license and one inactive license just for giggles and because it's occasionally more convenient to say "I'm an architect" when asked "What do you do?" than to describe what I actually do because I'm not exactly sure what that is beyond it being just the things I do.
There is (or was) a sort of standard student cannon in the US that included Ching's Form, Space and Order and Alexander's A Pattern Language. Alexander's work of course overlaps with software architecture, so it's "arguably" relevant either way -- though it's not a very interesting argument to me and so not one I'd wish to have.