I think that Wikipedia is a great idea. I have never liked limitations on access to general information and knowledge, so when I discovered Wikipedia, an encyclopedia that is free, and will remain so, it appealed to me right away.
I would never have thought that something like it was possible, because of the problem of vandalism, etc. But after seeing that it is possible, after all, I realized that it works because, in general, many more people are dedicated to building and fixing things, than to destroying things. It's also easier to fix things in Wikipedia than in the "real" world. Graffiti would be nearly non-existent in the physical world if anyone passing by could erase it by pressing a few buttons.
Though it's far from perfect, Wikipedia has already become quite impressive in many ways, and I think that in time it stands to become the most comprehensive, well-written encyclopedia in history. This is so because time is on its side. For the most part, it acts as a one-way accumulator of knowledge, organization, and writing quality, in operation 24 hours a day, with a huge team of contributors. These are all ingredients for truly impressive progress and achievement.
In other words, Wikipedia appears to be an excellent mechanism for harnessing the wisdom of a crowd, the idea that, given the right circumstances, groups of people can be smarter than any individual, no matter how expert on a subject. It largely meets the four requirements for a "wise crowd": diversity of members' opinions, independence of members, decentralization, and effective opinion gathering.
I've found that having so many others edit what one writes is highly instructive when it is done with intelligence. Whether or not your contributions remain in an article is a measure of their worth, and the ways in which they're modified are sometimes surprising. I appreciate being able to contribute.