Phrasing of question is do they "deserve formal credit from your home institution." No of course not, the class is free and they are not enrolled in the school. If the free class gets full credit, the university falls apart.
Also, giving real credit means you have to have money coming in, proctoring on site in their country for the tests, and id card checks. This will massively increase costs and completely eliminate the ability of people in most parts of the world from being able to take the class. One of the reasons for these classes is to open up western college style education to people throughout the world. Switching it to a pay model that validates identity just converts the whole thing into online extension courses, which they have already, and those certainly have never been MOOCs, enrollment numbers have been modest not in the 20,000-200,000 enrollment range per session (yes, with 10% passing but that means little, they still have huge numbers passing).