A few years back I had a serious lung problem. I visited my doctor, he recognized something is wrong (though he was not sure what it was) and send me to a specialist. The specialist did an X-ray, took blood samples eventually sent me to MRI, etc. etc. He determined that the condition is serious and sent me to a specialized sanatorium/institute that specializes in lung diseases and surgeries - along with the documentation collected so far. And they did their own X-ray, blood samples, and all the other tests. (At the end I ended getting a surgery) That was the standard procedure, and IMHO the right thing to do.
Recently I've seen a lecture explaining the basics of Bayes' theorem. That was first time I've encountered it. What I took away from that is: if you test positive, you don't jump to conclusion. You get the test repeated, you get more tests, you get independent opinion, ...
Why would someone demand or reject a treatment based on a single test not preformed by an expert is beyond me. But if high percentage of population is stupid enough to jump to conclusion based on single test not performed by an expert, then yes, you probably need FDA to regulate 23andMe.
It's one of those many, many problems that could be resolved by people being more educated.