I once had physical therapist who got quite far in the amateur natural body building world by only lifting 1lb weights. He was getting a PhD in Anatomy(!) and wanted to demonstrate that you don't need to lift heavy to get hypertrophy. Although he did not recommend this approach as the most time-efficient, he emphasized that gains can be made at the extreme end of the low weight-high volume spectrum.

What you say directly contradicts the article. Do you have scientific studies to contrast against theirs?