Loomis, like many things on 4chan, is a shit meme. The main principles he teaches is just
1, break everything down to basic geometric shapes
2, draw it over and over until it looks good
This is absolutely basic shit and common sense. His actual construction is garbage. Best way to learn how to draw something... Is to fucking look at it and draw it. You want to draw humans, look up videos on youtube of people doing poses for artists. Wanna draw a horse, look at horses. And really look. Understand how they work, their musculature, anatomy, how things bend and move, light and shadow.
90% of art is observation. This 'draw from nothing' garbage is not only intensely frustrating for a beginner but pointless most of the time since you'll use reference for the vast, vast majority of your work. I've never met a single artist who didn't.