Fair enough. Perhaps, the second option I proposed might work. The value of a Coursera certificate will not be reduced if it continues to be only a tiny minority who cheats.
I suppose I've always been of the opinion that they should offer the courses in a fashion similar to that of Khan Academy. I don't expect a certificate when I complete a section there as I'm there for the purpose of educating myself, not for accrediting myself. I think it's hard for Coursera to fulfill accreditation, but wish them the best if it's what they want to try for.