Unclear on why this is a good thing. Dumbing down language helps whom, exactly? I guess if you want to hasten the Idiocracy this is your app.
I'm considering applying this to my product documentation, even though our users are generally well-educated...we can't afford to have docs translated into a dozen languages, but simple English may be readable by enough foreign language speakers to make it worth the effort. English is a tough language; making it easier for new users of the language is great, IMHO.
It's also very possible to get the gist of a word, based on where it is placed and the words around it -- even if you don't know exactly what it means. (Obviously I'm not suggesting that for something like documentation writing -- but by the same token I would never think that limiting yourself to a 1,000 word dictionary for something as important as product docs would be beneficial in any way).
So, it's a joke, but maybe a useful thought exercise, too.
edit: i see that some are saying it's a joke. Poe's Law [0]?