Why 3D spatial thinking is neglected in school: testing on text vs. images

We know that 3D spatial intelligence is highly neglected in school despite being highly useful in life. But why?

My personal theory: "text" testing is more convenient and traditional than "picture" testing

There is a real irony in the current norms of academic testing:

We live in a society full of images - TV, internet, movies, video games, etc.

Yet, our school tests mostly on printed text.

Why? I can think of many reasons

1. Curriculum standards and textbooks drawn up by committees are typically communicated as a set of written concepts, vocabulary, etc. They are easily "checked off" i.e. "covered that" when the teacher presents the material in words, verbally or in writing.

But there are far fewer standards for the way information is presented in images. For example, one AP Biology class may be using cutting-edge 3D diagrams, another class may be using old diagrams that the teacher hasn't updated since the 1980s.

In turn, tests mirror the image-less way standards are presented: you just word test questions to include the phrases and vocabulary in the curriculum standards, that way you can "check off" that you tested on that concept.

But what if test questions asked for pictures, not words? These sorts of 3D questions are harder to simply "check off":
-"draw the heart from four different major angles"
-"create a basic 3D cutaway diagram showing the interior of a stratovolcano"
-"draw a diagram illustrating the potential energy and kinetic energy of a catapult before, during, and after release"

All of a sudden testing becomes a lot more complicated than simply looking for vocabulary words and checking off "covered that." However, it is definitely possible to use images and drawing in testing and it should be done much more. The teacher simply has to create a rubric for what each image question has to include.

2. Most school tests are given on paper. It would take a lot of paper to add 15 or 20 images to a paper test. However, computerized testing is making images much easier.

3. For a teacher to even think to include 3D visualization concepts as an essential part of a class, the teacher typically would be a 3D thinker himself, which we know is not always the case, even in the sciences.