I think the intersection of diet, training and goals can't be understated. I think they are equally important when getting bigger and stronger and that the percentages shift when cutting or refining.
If all I wanted to do was get bigger and stronger not worrying about shape, I would just train hard and eat. But, I AM concerned about my overall look, so I to focus both on how I train and what I eat.
Now, I don't micro-manage either. I train sensibly and tread lightly when I am injured (which it seems I always am). I eat the same basic meals during the work week and whatever I want on the weekends.
I've gained muscle and I've gotten stronger. If I were concerned about being very lean, I know I'd have to be more precise. I'd get help when and if I seriously wanted to cut say, 20 pounds. I'm not there yet.
The kids on the internet want to get bigger and yet still want to be lean. They don't understand that there is this period of time where you have to get big without being lean in order to be able to lean down. They aren't able to delay gratification, and that is why they chase their tails and stay small-- chasing a 1 pound gain over 2 months.
Complication makes it easy to explain failure.