If they want to sell DNA dumps and call them DNA dumps, that'd be truthful advertising. But if they want to make diagnostic claims, they need to actually back them up.
That's the point. If they simply gave people raw results and told them to Google it, that'd be fine. They could even provide a report with hyperlinks to SNPedia. But that's not a very fun marketing message, is it? 23andme wants to sell itself as accurate diagnosis, without having to actually prove they're accurate. The FDA's letter said the FDA tried to contact them repeatedly about this issue, asked them to change language, and 23andme ignored them. What's the FDA supposed to do?
They should crawl back into their bureaucratic cave and carve some hieroglyphics into the walls with pieces of flint, or otherwise find some way to occupy themselves while the world goes on quite well without their unnecessary interventions.
They can't have it both ways. They can market and dump out your DNA data. Or they can meet regs, prove they are clinically accurate, then market it as a diagnosis product.
We'd not like random companies starting up and misleading people and claiming to diagnose but really just flip a coin. That's all the FDA is asking.