A WikiHijacker will swoop in on a wiki and post content suggesting that the really good stuff is elsewhere (usually on their own site). This is especially troublesome for newly emerging wikis that are trying to develop some meaningful content and some participants (readers & authors). When a WikiHijacker shows up and creates seemingly OnTopic pages with little more than a link to their own site, it zaps the energy of the community. It redirects their attention away from the wiki. It tantamount tells them that the new aspiring wiki is little more than redundant.
Some antidotes against AttentionTheft are:
The main reason for not taking the LinkFarm path is that through the process of reading and in writing, one can learn and develop new knowledge. If you buy an encyclopedia, you have about 200 lbs of paper that you might be able to use to reference from time to time. However, if you write an encyclopedia (or better still, support a place for many people to write an encyclopedia, e.g. WikiPedia), you foster the creation and sharing of much knowledge.
What do you think of Wiki Nodes?
These are basically pages that tell which wiki are closely related to the immediate wiki.
I think the main reason you want to avoid a LinkFarm isn't because we think we should all reinvent the wheel over and over. The reason we want to avoid a LinkFarm is because most of the targets in the LinkFarm aren't publicly editable. And they rarely "mesh well" with the other link targets.
Wisdom and Wiki are characterized by integration. The LinkFarm points to stuff, but doesn't integrate it.
At least, that's my take on it.
Nobody move! We're taking this wiki to Cuba! Now does anybody know which Interstate we take to get there? Easy - the same one that goes around Oahu, Hawaii. If it can get to one island, it can get to another!