Unfortunately, Plan B Contractors can also, and often do, result in an aborted project due to the prohibition of the tile/thinset combo sticking to the backing wall.
Any argument against that must then either redefine the reality of constructionology (i.e., what the tile/thinset combo is, singly or collectively considered), or must recognize it as a separate entity from wallness. With that argument, one could put a hammer through a single tile-in-place and technically not punch a hole in the "wall".
A tile without thinset simply falls from the backing, no problem; thinset without tile simply hardens in a white mess (though this gets into other areas of constructional ethics). Together, they form the beginnings of a wall, and substantially are a wall, even if not accidentally a full wall in its various stages of construction.