Almondmilk is mostly water and thickeners. A typical 32-oz carton uses around 12 almonds. You can tell by the protein content of all of these altmilks how cheap they actually are to make.

The only exception is soymilk which does actually have a lot of protein and also has a really long tradition. People have been making soymilk for over 2,000 years. American grocery store soymilk is quite different but you can actually go to an Asian grocery store and still find soymilk that has a single ingredient.