Nice strawman. It's great that there's restrictions preventing dangerous stuff from being put into food. But the issue here is not being able to avoid dangerous substances, but whether or not Soylent is sufficient. You're deflecting the discussion onto something entirely different.
Unless you are claiming that these guys are likely to put dangerous, non-FDA approved substances in their product?
The comment you respond to makes the point that while there's plenty of possibilities for dangerously deficient diets at any grocery store, and lot of people do choose diets - from regular grocery stores - that are extremely limited, most of us do ok.
And that is what Soylent needs to match or beat in order to avoid doing harm. The bar is extremely low considering some of the stuff I've survived on for extensive periods of time, and the type of diets I see others manage on.
That's not to say that they shouldn't aim higher, but there are a lot of people here that seems to be completely oblivious to just how shitty diets a lot of people live on.
That said, I think their marketing claims are well in excess of what they have evidence for, and it saddens me a bit that they feel that hyperbole is necessary. I also hope they put a lot more effort into testing.