A WalledGarden in wiki terms is a block of content which may be topical, but is not integrated into the rest of ExaltedWiki. The classic case is a UserPage which has only 1 link in (the master user page index), and then links to several (on-topic) pages internally.
- (Actually, UserPages probably have more links than any other type, since people sign their comments with their names. - Raindoll)
Wikis will continuously form small WalledGarden's as they grow and new content is commited. As that content is integrated and linked with the rest of the wiki, the content ceases to be a WalledGarden.
A special case of a WalledGarden is an Archive like the WriterQuotes. These may have many links in but contain almost no links out. This is generally considered the correct course of action for such content.
On these, DaveFayram suggests:
To a limited degree, this is acceptable. The WriterQuotes section is a good example of a scenario where this is okay, because for archival purposes WalledGarden's are inevitable. However, when we're writing regular wiki pages.
Why is this ConsideredHarmful? The content may be good, but it is difficult to integrate such content with the rest of ExaltedWiki. The heated PrettyWikiProject debate, the problems of WikiOrganization, and the generally poor navigation facilities of this site are all symptomatic of a wiki with too many WalledGarden's.
To a degree, UserPages will always be WalledGarden, but we should try and integrate our UserPages with other UserPages and content much as possible. The whole point of the wiki (as discussed in BestPractices) is to allow individuals to link content together. WikiAsAMicrocosmOfTheWeb isn't really a good model to follow.
This is more of an organizational issue than an ideological issue.
See also: UseWikiWordsNotBracketLinks.