Just an idea, but you'll probably find your time better spent building and submitting a doc, than complaining to your potential future employer.
Academically, he's trying to serve up a point. But he's potentially doing more damage to himself by doing so.
I don't need a job right now and as I mentioned elsewhere, this kind of thing usually takes a company out of the running for me anyway.
I'm not in need of a job right now, I am poking around because I'd like to have some side work for when I leave the country. Not mandatory by any means.
Just an idea, but you may want to get off your high horse and go do something useful other than criticizing people trying to discuss something.