[owyn]

I don't think that's true, even if you look at most open source software. On one extreme, Mediawiki is a pretty complicated piece of software, approximately 900k lines of "core" PHP/JS code plus another 1.5 million lines worth of extensions, many of which are pretty mandatory for basic functionality.

Is it "good" or "bad"? I'd argue that it's both. It's an important piece of software but a bad architecture, and it's grown in complexity over the years. I think you could write a piece of functional wiki software in about 500 lines of code, but complexity and features win in the marketplace, even if it's just for "mindshare".