So, why the discrepancy between the two points of view? I suppose you cold write it off as the difference between some ivory tower intellectual snobs on one hand and a bunch of uncritical fanboys on the other. I do not think it is that simple. The academics are looking for by lines and some form of accountability for the content they view online. The music fans are interested in finding out more about their favorite bands and getting a more complete picture of the people in those bands. The different goals lead to much different views of the value of wikipedia.
When all else fails, look to motive. The academics are looking to pad their CV and to secure positions in academia. Contributing to or using wikipedia is not going to help them in their quest. On the other side, looking to fanboys for motive is missing the point. Look to the bands they are following, they have a motive to get their image and music out there as much as possible. A wealth of online content could help them in that endeavor.
The mixed motive behind commercially oriented wikis like wookieepedia and other large wikis hosted by wikia.com may indeed be inadequate. There is a serious component that is just that there are people out there who love to discuss their hobbies. Be it marvel comics, recipes, genealogy or that massive time waster world of warcraft, some people just love to carry on about the things that occupy their spare time.
The idea behind wikis has been put to some good use to create collaborative history projects and school related wikis for various purposes. Also, some wikis have been set up for groups that are not great in number or media access, such as a neopagan wiki or a traditional witchcraft one. So with all this wiki rambling, is there any kind of conclusion I can draw from this? I would say that wikis can be used as a learning tool, a way for virtual communities to come together and for commercial properties to promote themselves. For a more serious version of wikipedia, check out citizendium. Personally, I think that wikis are good sources for information that you are curious about, but it really doesn't matter if the answer is right.