I'm a bit surprised that this hasn't been suggested by now, or isn't coming up in the search. At any rate, I'd like to have the ability to download an entire wiki as a set of text pages in a ZIP file.
The simple fact is that some wikis outgrow WIkidot. Wikidot is a great tool for creating simple databases and filling them with data. It does a decent job of giving you ways to present that data. However, some sites reach a point where they need more sophisticated data retrieval, querying or display.