Alright: I generally do call them directories. I grew up in UNIX. But we're talking about icons and UX here. Do you consider the "desktop" to be so infantilizing as well?Why yes, yes I do. Desktop environments are all attempted answers to the question "why is a computer like a writing desk?" The question is absurd in its own right, but carries additional absurdity baggage such as calling all files "documents". A movie is not a document. A computer program in binary form is not a document.
All of my machines boot into bare-ass window managers -- typically either awesome or WindowMaker. It's simple, cruft-free, and leaves more room for the programs I want to run. Aside from the shell I find an activity-based model for launching programs -- such as found in iOS, Android, OLPC, and even Windows 3.1 for pete's sake -- to be infinitely preferable to the document-centric desktop model, which assumes that the user can't fathom a computer without the machine pretending that it is some older, non-computing, manually-operated piece of office equipment.
Even if the terminology originated in a Windows era -- it didn't. It started with the 1984 Macintosh. Funny that, even Apple is moving toward an activity-based model for iOS.