A wiki is only as good as the people adding the information. As a resource tool for people of like interests, specific literature, art, etc it is great. If it is a one person wiki it is nothjing more than an editorial page for that person and the information can be slanted or totally incorrect.
If you choose to use a wiki as a starting point for a project or interest, fine. To make sure the information is correct more research will have to be done. Libraries, librarians and the information they have available may be a bit less "tainted"!
A wiki is a toolo like any other tool. Used incorrectly it can hurt you.