This is a maddening problem that's evident on even the lowest of levels. A while back I helped tutor a high school kid who was taking a geometry class online. His instructor had written electronic articles to supplement a textbook, but still did the same "skip a bunch of steps" nonsense that the textbook did, even though he had no real space limitation.

He (his mother, actually) asked me for help because (1) he wasn't a strong math student, and (2) he was absolutely stuck trying to follow some examples that purported to explain the first homework assignment.

When I tutored him, part of what we did was go through a couple of the examples micro-step by micro-step, identifying the assumptions and algebraic simplifications that happened along the way. This made him feel a whole lot better - he could grasp the new material more easily when it didn't take him 10 minutes of figuring out what old material had been already applied to the examples.

I write tutorials online occasionally, and try my best to not make this same mistake.