I think that Soylent will go down as a cautionary tale for anyone who looks at a field they know very little about and thinks "how hard could it be?". Along with Theranos.
What Soylent should have built to be worth $100+ million is a way to make a food product tailored to a particular person or group of people that's based on automation and nutritional science.
Instead they seem to have a cobbled together amalgam that they don't really understand. If it hits 25% DV down the board and nobody dies then it's a job well done.
We know that different people have different dietary needs. The RDA system is by design generalized, not personalized. The RDA for iron varies between 8mg and 27mg [1] for adults but the DV is 18mg.
Meanwhile Soylent Powder 1.6 provides 5mg per serving [2] and calls that 25% (it's actually 27.78% Soylent, check your math). That's way too much for an adult male if you have any other sources of iron. And it may be way too little if you're a woman with no other sources of iron.
Not to mention that all sources of iron (and other nutrients) aren't absorbed equally. Iron from plants is absorbed half as well as iron from meat -- since Soylent is vegan, should we put a discount on the %DV it says it provides?
This isn't an easy problem to tackle, but building a system that understands nutritional science and adapts the product accordingly would actually be a worthwhile endeavor. It would also mean manufacturing and testing in-house, which Soylent doesn't currently do either. Build something worthwhile, not a slick website hooked up to an outsourced assembly line.
[1] https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/#h...
[2] http://files.soylent.com/pdf/soylent-nutrition-facts-1-6-en....