Why vision documents stink

At a talk yesterday I asked an audience of program managers how many of them had read a vision document. Most of the 100+ in the room raised their hands. I then asked how many had read a document they thought was good: about a dozen kept their hands up.

I’ve asked this question dozens of times and it’s rare to find people who’ve read one they thought was good. Most teams (or start-ups) have some kind of written charter, even if it’s just a beat up e-mail, for what the over-arching goals are supposed to be.

Why are they often so bad?

I have 3 theories:

They’re often written by committees. Five people get in a room and yield to mediocrity. Unless one talented person asserts him/herself as the lead author (e.g. Thomas Jefferson) the result is jargon happy, wishy washy, impenetrable tripe. You want a clear narrative, not a labyrinthine wishing well.
They’re not written to serve the reader. What purpose do these things serve? If the people writing it don’t know, odds are slim what the write will be of use to the people asked to read it. If the goal is to catalyze, motivate or clarfy, it should be easy for any vision author to check with readers to see if it’s working. But if they don’t ask, readers might be afraid to tell.
Author confuses hype with reality. A good vision document connects the future with the present, and gives tools to people to make faster decisions. All the hype and conjecture has a place, but it’s probably in the supporting materials, not in the directives or goals people are being asked to follow.

So why do you think vision documents and their ilk are often so painful reads? Politics? Cowardice? Lack of imagination? Labotomy? what?