I was surprised to learn that most chose to do them online so that they can cheat on the tests. Free from instructor supervision all tests were open book and thus were much easier than taking them in person.
While many of us have high ideals for online education, I've learned that the majority of students get a degree for the diploma first and the education second.
I think that it really depends on the class. I know that the finals for certain MOOC courses I took were very difficult indeed, and it was absolutely impossible "google" the answers. Even with the open book and notes, the tests were challenging enough that these cheating mechanisms were pretty worthless.
Also note that there is a wide diversity in the course quality. Many of them are super easy and watered down to the point that it is meaningless, while others are quite challenging. While I wouldn't expect an interviewer to know which class falls into which category, just realize that many of these certs are virtually meaningless regardless of the results.
I've pondered creating a site for ranking the MOOCs that are available now, to serve both the students who take these courses and the employers who are facing these students.
Either way, the complaint of "diploma first" feels a bit off-hand. If people are finishing college without knowing how to program fizzbuzz, what is the difference between the good and the bad? Clearly it isn't the quality of the class: it is the quality of the person regardless his or her background.
What's surprising is that three months ago we've heard a completely different story:
http://www.nytimes.com/2013/04/30/education/colleges-adapt-o...
"Usually, two of every five students earn a grade below C and must retake the course or change career plans. So last spring, Ellen Junn, the provost, visited Anant Agarwal, an M.I.T. professor who taught a free online version of the circuits class, to ask whether San Jose State could become a living lab for his course, the first offering from edX, an online collaboration of Harvard and the Massachusetts Institute of Technology.
...
The results were striking: 91 percent of those in the blended section passed, compared with 59 percent in the traditional class."