This stuff has existed for years and there are probably thousands of "certification programs". Most of the time, they're deemed worthless.
Why can't we have free online courses for everyone, where the only costs are the actual free market costs that go towards staff required for administration, courseware development, instructors, and test proctoring?
Why should a college degree from an online university cost a fortune, if the course material remains mostly unchanged from year to year? At the end of the day, all you need is the educational materials, someone who help guide you through them, and then a test to prove that you learned the material. Why isn't that good enough??
These costs are not exactly negligible, though they are much less than the prices charged by private 4-year colleges. The average community college tuition and fees is only $3400 [0]. That's fairly close to the "free market" cost of providing tutoring, creating new tests, test grading, and other administrative fees. So, I think the real reason is that there is not much of a market to be had since---if you don't need the signaling, research, or social aspects of a 4-year college---community colleges already offer an arguably superior product for what would be a similar price.
[0] https://bigfuture.collegeboard.org/pay-for-college/college-c...
Accrediting Khan Academy (or Udacity, or whatever) won't change any of this process. Employers don't have an incentive to change their process right now, so in general students would not pick something like an online degree over traditional university.
Obviously, if the material and teaching sucked, or if cheating was rampant, that would tarnish the reputation, but the same could be said of virtually any educational institution.
There are potential ways of addressing this, but they mainly involve the online university developing selection criteria just like elite colleges (e.g. everyone can access basic materials, but only certain X performers can access the premium version with company interviews; or they only admit X students per class). Otherwise the value of the degree is diluted and it has no more signaling power to employers. In addition, the online universities will likely attract less capable students, because for very strong students, top tier universities are still very much worth it.
You need some way to get your foot in the door and prove your chops. Some bootcamps like Lambda school are doing a pretty good job about that