The point isn't about whether Wikipedia is an excellent/easy source for information though. It's about what counts as a source you can cite.
The thing is that with primary sources (unless your topic precludes the use of such things) you can produce new useful work. If you're simply regurgitating established views created by others, you offer very little to the field. Academic research was once very inclusive of secondary material because they felt it unnecessary to look again at an event, and simply go on with what people have already said of the subject. It resulted in persistent errors in many fields, especially history or anthropology.
The rationale is like this. If you wanted to see if a math theorem was correct, would you ask someone about whether he thought (say the man was Euler or Einstein, just so that it's not some random fool) it was correct and then use that to prove the theorem was correct or would you actually go get the theorem itself and test it rigorously?
edited 23rd Feb '11 12:55:46 PM by breadloaf