Have you worked in those fields? I worked as a commercial interiors contractor, then worked in embedded systems doing (among other things) board design and layout. These fields have plenty of iteration that has to occur. Pretty much no one ships a rev A board, chip, or bridge (the bridges get built out in solidworks).
It's not a very strange thing to say at all - It's the truth. The Waterfall software method is a result of a misunderstanding by the DoD.
Waterfall as far as software is concerned has its origins in a paper from Winston W. Royce and not an unguided adoption of mech/civil/electrical engineering principles: http://www.cs.umd.edu/class/spring2003/cmsc838p/Process/wate...
> They didn't agile up the building you're sitting in
Do you know where I'm sitting?
That is a very strange thing to say considering that the method comes from "real" branches of engineering (mech, civil, electrical, etc) and you can simply look around you at your built environment to know that it has delivered an awful lot of real, actual stuff. They didn't agile up the building you're sitting in or the roads that lead to it or power station that makes it work or any of the things in it.