This is my take on it
1. Young ectomorphs (that's the tall and/or slender ones) can really benefit from getting as many calories down thier neck as possible, from whatever source.
One small problem with this, eating a less than healthy diet does develop bad eating patterns, and what you can 'get away with' when you are 16-30 ish isn't what you can get away with for the rest of your life.
2. When people want 'insta' muscle, they do focus on the short term gains and 'brag' about them.
Is this approach going to work in the long term?
Probably not.
3. If you rely on the drugs to make up for shortcomings in your diet and training, you really are shooting yourself in the foot.
You may not be able to juice for life, there are more reasons that health. Even if you avoid the legal aspects of it, there are a number of professional occupations that would frown severely on any drug use (even alcohol), as some professionals are responsible for the well-being of others, and anything that could alter their mental faculties would just be irresponsible and reckless.