No-one can dispute that Wikipedia is a useful source of information in many areas. It's strong on mainstream science, computer programming, cult television, video games and anime. These are the subjects that get a typical Wikipedia editor's pulses racing. In other areas, such as history and the fine arts, they shrug their shoulders and leave it to people who are knowledgeable in these fields. Only Forteans are seriously persecuted... Wikipedia doesn't share their interests, but unlike classical music and Greek philosophy (which they don’t like either) they just won't leave us alone.
What Forteans understand, but the average Wikipedia editor can't be bothered to, is the perfectly clear distinction between a phenomenon and the description of a phenomenon. The latter can be totally neutral, verifiable and factually accurate even if the former is not. This is true in the case of the Wikipedia article on the Dean Drive, from which the above warning notice is taken.
There are a couple of other reasons why Wikipedia has got it in for Forteans. One is its "policy" WP:FRINGE, which discriminates against any idea or theory which is not part of the mainstream curriculum -- even if that idea or theory has significant social or historical significance. Another is its strange concept of "notability", which seems to be based on the principle "we haven't heard of it even if you have". As a result, many subjects that will be household names to Forteans have had their articles deleted from Wikipedia -- Timothy Good, Alan Godfrey, Charles Fort Institute, David Clarke (lecturer) to name but a few (these are links to the relevant deletion logs, since the articles themselves no longer exist!).
Even Jenny Randles, one of Britain's most prolific Fortean authors (and, like most British Forteans, a highly rational writer far from the rabid ET-believing stereotype that Wikipedia imagines us to be) is tagged for "notability"... as is the Owlman, one of Britain's best known cryptozoological phenomena.
The Fortean Times UnConvention has been running for almost two decades, and is the only event of its kind in the world. A few years ago, Wikipedia had the beginnings of a good article on the subject -- the archived version still exists. But now, if you type UnCon into the search box, you are redirected to the article on Fortean Times... because, we're told, UnCon is not notable except in the context of the magazine!