During the kickstarter they made a number of bullshit claims: "puts you in perfect health"; "perfectly safe for anyone"; they claimed rigorous testing which appeared to be one person living off it for a few months; they advertise it as a sole source of nutrition without any real testing.
This just seems to be a biased claim that Soylent hasn't done any "real testing". Do you have evidence of that? Soylent has been out for years and a lot of people have been drinking 100% Soylent for a long time now.
They hadn't done any testing during the kickstarter, and even if they had saying it was fine for anyone to use (the original recipe contained known allergens) and that it puts you into perfect health are clearly bullshit.
(EDIT: I don't know why you're being downvoted. I upvoted you to try to correct that.)