He says:

"Stanford “free” classes aren’t free. Stanford students have to pay for them. The fact that I’m paying for them doesn’t bother me, the fact that people who aren’t paying for them have changed the class more than the ones who have, does."

which does seem to be a forceful point. However, checking the FAQ (http://see.stanford.edu/see/faq.aspx#aboutq2) we find that they are funded completely from outside sources. So this guy didn't even bother to do some basic Google checking.