So, Soylent push it as a sole source of nutrition, and some people use it as such, but then when there are problems people say "but you shouldn't do that", even though most of the people experiencing the problems aren't doing that and even though it's something pushed as possible by Soylent.

If you can use Soylent as a sole source of nutrition there shouldn't be anyone in this thread saying that Soylent is never meant to be used as a sole source of nutrition.

If you can't use it as such then Soylent have been irresponsible in their marketing (although they have toned it down a bit).