The image of wikipedia editors jealously guarding pages (which makes me think of a dragon hoarding treasure) is entirely accurate and widespread. I've seen it happen on all kinds of pages from pages about some religious event/person to pages about highly technical subjects. I honestly don't know what the solution is because there are definitely people who continually try to edit history by changing wikipedia pages, but the scales right now are way tilted toward preserving bad info, which includes fixing errors and also adding expansions.