In his recent book on writing (The Sense of Style), Steven Pinker suggests that the economic concept of the curse of knowledge is the main cause of bad writing.
Call it the Curse of Knowledge: a difficulty in imagining what it is like for someone else not to know something that you know. …
It simply doesn’t occur to the writer that her readers don’t know what she knows – that they haven’t mastered the patois of her guild, can’t divine the missing steps that seem too obvious to mention, have no way to visualize a scene that to her is as clear as day. And so she doesn’t bother to explain the jargon, or spell out the logic, or supply the necessary detail.
Here is Wikipedia on the curse of knowledge:
The curse of knowledge is a cognitive bias that leads better-informed parties to find it extremely difficult to think about problems from the perspective of lesser-informed parties.
And LifeHacker amplifies:
If we extrapolate these results to communication in general, it means that we think people understand what we’re saying a hell of a lot more often than they actually do—because we’re so used to knowing the things we know that we expect others to know it as well.