There is a resistance. I don't know exactly why. Textbooks I've used recently do tend to begin with the equality property and a few other properties that are needed as a foundation.
If you haven't been in a school lately you might not be aware that textbooks, at least in the places I've worked, do not exist. There might be a few leftover texts on the classroom shelf. In "Stand and Deliver," the actor Edward James Olmos, channeling famed math teacher Jaime Escalante, began his illustrious career by having students turn to a certain page in a textbook. Astonishingly, IMO, there are no class sets of textbooks, let alone a textbook for each student. Teachers then spend a lot of time reinventing the wheel.
The temptation is to try to cram knowledge into their heads efficiently - boot camp! - but it doesn't work that way with many students. They need to be doing math, not listening to explanations (though sometimes explanations are needed). It's a balancing act.
The Saxon textbooks for lower grades gave lessons in chunks the size of an index card with everything after that being practice, including reference, with page numbers, to earlier lessons. The high school algebra textbooks I have are so graphically busy (boxes, hints, fake highlighting, blurbs about famous mathematicians, photos etc.) that it's hard to focus on the kernel of knowledge leading into that day's practice.
