Conclusion: muscular hypertrophy is only one of the mechanisms skeletal muscle have to become stronger and it is secondary in activation to several others. To achieve muscular hypertrophy, huge weights with low work load is ineffective because there is enormous room for your muscles to grow in strengh before growing in size. You'll need to use gigantic weights to achieve only a moderate degree of hypertrophy with a few contractions.
Conclusion II: To maximize hypertrophy, increase strengh enormously first via powerlifting or one-set-to-failure protocols, then stagnate the weight you're using and work on increasind the amount of work you can perform with that weight. Huge gains in the cross sectional area of muscle will follow. Once volume has increased to the point where you have observed that your gains have stagnated, work on increasing your strengh agains via powerlifting type training. Repeat ad infinitum.
SUCKMYMUSCLE
I agree, but I think another important factor you left out is variety of exercises (different angles of stress). Most powerlifters and HIT trainees do a stubborn selection of routines, whereas a big bodybuilder does a wider selection of exercises.
Most HIT people think different angles of stress is unnecessary and argue that the muscle "can't be fooled". They believe that a compound movement is sufficient in stimulating maximum development, which I believe is incorrect. The human body is capable of so many movements that simplifying it to one or a few movement will not get the goal of maximum muscular potential done. Don't get me wrong, you can get a lot of bang for your buck with abbreviated routines, but not complete muscular development.
For example, if all you did was squat, you will get strong and very good at the movement. You will put on muscle. But, if you later on incorporated leg extensions, leg curls, and other leg press variations, you'd find you will be lacking in strength in the areas. People who regularly only do the latter will most likely be better than you, despite you probably being better at the squat than theses same people.