The work by Kop and Fournier (collected here – http://ritakop.blogspot.ca/2012/01/research-publications-on-massive-open.html (I don’t know why everyone cites the 2014 EdX research but ignores this earlier research) on the population served by MOOCs also found that it was an older and well-credentialed demographic.
But I wonder how relevant this is. The 1994 surveys of internet users http://www.cc.gatech.edu/gvu/user_surveys/survey-01-1994/graphs/results-general.html show that the average user was North American, educated and professional. They were also overwhelmingly male. But it would have been incorrect to conclude from this data that the internet would not have a broad society-wide utility or appeal. It shows, simply, that there is a characteristic demographic that benefits from innovation earlier than everyone else.