Other “construction trades,” in fact all of them, routinely succeed in doing what the software development profession routinely fails to do.

By "all", of course, I assume you mean "none" -- otherwise I'd have to question whether you've ever actually seen anything ever constructed, let alone been in a building. I've worked construction myself, and I have a couple of friends who do HVAC design and sheet metal contracting. For every building ever built without a stack of change requests piling up the day after bid approval, I can show you a space shuttle software project at NASA (and there's only one of those).

I think that when we run around bantering strategies with funky-but-upbeat sounding names like “agile” and “extreme,” all the while claiming that such things properly belong only to our storied ivory tower ... we're ... well ... we're just plain wrong.

We call it software for a reason. Okay, Fred Brooks calls it "pure thought-stuff", but that's still at least somewhat different from the thirty story townhouse tower they built downtown here. You know, the kind where they have to dig a really big hole first, then sink pilings, and if they decide they need five more stories as they're hanging drywall inside, they're stuck thanks to the inexorable laws of physics and material science from their civil engineers. Meanwhile, we add a few lines of code and maybe another stick of memory.

Is this not a fundamental difference?