This is not artificial food any more than bread or cheese are artificial. Also, the scientists developing this technology are not advocating that people only eat Solein; in fact it seems like they're marketing it more as an extra ingredient that can be added to other foods that will increase the protein levels.

It also seems like you're confusing this company with companies like Soylent that are trying to create a nutritionally complete smoothie. You're correct that we probably don't understand nutrition well enough yet to make a single food that would lead to optimum nutrient levels, but in my opinion it doesn't really matter. Almost all humans are somewhat nutritionally deficient; eating a food designed to have optimum nutrient levels will probably make you less deficient than average and you can always supplement a Soylent diet with other foods.