Wikipedia is under constant pressure to police the accuracy of its information, and that typically means leaving the moderation to millions of engaged users. That approach is fine with me, since I usually use Wikipedia to find out what everyone else knows about something; whether or not the info is true is a secondary consideration. But if less people engage in the content creation and moderation the quality of the information could go down. And that's a problem when these pages embody, and perhaps create, conventional wisdom. It's safer when there are more people who edit the entries, and thus more people who hold the power of truth (or truthiness) in their hands.
Luckily right now there are more than three million people who write, edit, and check the information, guaranteeing some level of oversight. Let's hope Wikipedia figures out how to keep them coming back. Have you ever contributed to Wikipedia?