We provide regular database dumps to make the information freely available in a manner that is friendlier to our servers, and that is usually easier to process and import - it's much more convenient for both parties to import all the revision text at once, rather than crawling for it.
The last time the full enwiki dump (All pages with complete edit history, pages-meta-history.xml.7z) completed was on 2006-11-04. Any idea if the current one will finish?