I think a lot of it has to do with genetics. No matter how much I work out I'm always going to be skinny. Then I see other folks that don't have to do anything and they're naturally "thick."

the article says do only one set and train once a week, i think the article should be titiled "how not to build muscle". And what are those scientific principles? Any references?

I THOUGHT this was true! I use to work out a lot, and, never seemed to gain strength. When I said "screw it", and, only lifted weights a few times a week, strength improved. All those protein drinks I took, just made me fat. What muscle I gained with them went down the drain, litterally, when I lost the weight. What came on fast, went off fast.