Apologies for the delayed response. I hadn’t checked this topic in a while, being caught up with end-of-semester teaching duties and such. Anyway:
The clef-with-8 notation was invented for the benefit of students and others who don’t already know that certain voices and instruments transpose by an octave.
It’s true that the octave treble clef was created in an effort to “rationalize” writing for the tenor voice, so that it would sound in the indicated octave like other voices. However, the extensions of this principle were (as far as I have seen) initiated by composers seeking to avoid a clutter of “octave higher” dotted lines (or leger lines) in their music. Britten, for one, would use it in his piano writing for unusually high treble or low bass passages. It has a very specific musical function there, and is certainly not a concession to the ill-informed.
I in fact wasn’t aware of their use for octave-transposing orchestral lines, and am just as much against that as you are. One of the first things I have to emphasize to my orchestration students each year is that piccolo and contrabass transpose the octave automatically, and you don’t have to (indeed, must not) do anything additional to signal the fact. So, when I use such clefs (rarely), I mean them to pull their weight.