Most people aren't clamouring for a return to 28.40d. There are only a few things causing issues with the user base. By far the largest complaints are: 1) New style channeling removes functionality that is needed, therefore please return that missing functioality, 2) military is buggy and hard to use, therefore please squash the bugs and refine the screens to be somewhat more intuitive/easiier to use, and 3) can we please have one automatic mapping of "indoors" for warrens so we don't have to constantly be updating the "inside fortress" warren?
Note that the first, lost functionality in channeling, is a very loud voice. Its absence is causing significant problems for the users. The player base doesn't care if the new "down ramps from above" stays, just that it gets back its missing functionality.
The second, military, is split between "bugs" (including "balance" issues) and easy usability. The player base with DF is used to having to go through a slog of screens and commands to get anything done, but the military screens do add another full layer of slog to do the most basic tasks. However, we can note that the player base sees the potentional in it, so they are just wanting the bigger bugs chased out, and the screens to get some (not final product quality) refinement.
The final issue bothering the player base is that there isn't a quick "inside" warren command. It is a bother to constantly build the equilavent burrow by hand, especially if all they want to do is get everyone and the stray animals to run into the fortress and shut the doors and raise the bridges. Players do like the new warrens, due to its potentional, but the constant updating of "inside" bothers some.
I don't see anyone clamouring for a return to the old "material" system, the removal of hospitals and healthcare, nor the removal of caverns. Just a user base wanting lost functionality restored, truly signficant bugs addressed before Toady moves on, and a lot of "Wow! Cool! This is great! And imagine it once the bugs are squashed! It will make the most awesome game become even more awesome!".