When browsing guides at GameFAQs, and later writing one myself, I've noticed the shortcomings of the fixed system.

1. Quantity, not quality
   When I want to find tips on beating a certain mission I often need to read several guides just to get what I want. Some list the popular strategies for a mission, others allow readers to contribute their own ideas, while the vast majority choose one sole path and stick to it. Some guides are overly stupid--"shoot the guy to the left. Then approach the dealer. Kill him. Take his car north to the Pay 'n' Spray"--I don't NEED info like that.

Now there are some advantages to writing your own FAQ instead of collaborating.

1. Personalisation
   You can, for example, say things like "I finished these rooms all before the third chime!" Or put in little jokes. Or whatever. Things that are OK in your own guide but not in an ownerless one.
   
2. Attribution
   If I write a GameFAQs or IGN guide I can pimp my contact details and ID all through it, and you'll find it linked to on my user page, and everything. With wikis, there is often no contributor list, and certainly no-one gets the "credit" for the guide, as it was a group effort.

In comparison, what does the wiki environment offer...?

1. Visitor upkeep
   So often I read a FAQ and spot a typo, or a spelling error, or a mix-up of the mission specifics, or whatever. Now in a wiki I can just jump in and fix it, whereas with a guide I have to find the guy's email address, copy it into Gmail, write to him, hear back a week later if at all, and finally see the fixes come up in an updated version a month later... all the while others stumble across that error and think they're doing something wrong.
   
2. Multiple viewpoints
   Sometimes you just don't know the best way to describe a mission or objective. With a wiki you can jump in and help out by improving others' contributions
   
3. Instant
   Just today I was making some minor improvements to my BS Zelda: Kodai no Sekiban FAQ. Now I only have time to do a few things right now but the problem is that the GameFAQs' addition delay is so slow that I really feel I have to hold off until a major revision to upload anything, and every minute that goes by people are reading the old crappy edition.
   
4. One guide, one version
   Right now I keep an annotated HTML master copy of my guide, and then simply remove the annotations column when I go to "publish" it. But with a wiki the only copy I need is the wiki; for the entirety of my GTAIII guide I never made a single offline copy except for the few missions I wrote up before the launch.

But what is the wiki environment doing "wrong"?

1. No promotion
   Wikibooks and Wikicities are virtually unknown places. Their guides are not marketed in any way, so the only way for visitors to come is manually. For about a year now I've been advertising the San Andreas and GTAIII guides in my sig, with good results, but that's still not enough.