From a managerial point of view, information repeated all over the place becomes unmaintainable. I hate it. Even some question answered in the dim and distant past that has become inaccurate in the process of development can still come back to haunt when a search engine jockey picks it up and believes it without further investigation. I would much prefer obvious links to the relevant information, kept all in one place* and updated when required (even that isn't easy, but it's a lot easier than the alternative).
Unfortunately there is nothing we can do about human nature, there will always be people who can't be bothered to read up - however it is presented. The best we can do is make the signposts as conspicuous as possible, embarrass them into reading it, and if all else fails answer the dumb questions. I still ask dumb questions from time to time.
* We have broken that already by having the forum and the wiki. In my opinion, the forum discusses current topics and arrives at information (which then becomes frozen) whereas the wiki should be written to capture and summarise the information once it has frozen. I don't have time to support both, which is why you find me on the forum and not the wiki (which I only use occasionally for reference). However, the wiki entries should signpost back to the sources of information, and the forum entries should signpost to the wiki wherever appropriate. By maintaining a web of links, it is possible to traverse them, review and update burried information when necessary, if anybody can be bothered (which I do, when I am looking for something, and spot a problem).