Language-learning Gurus

I refer to Lýdia Machová, Steve Kaufmann, Gabriel Wyner, Robin McPherson... as examples of "polyglots" who claim they speak 6, 7, 8, languages fluently and add a new one to the list every two years or so.
Each one of them claims he/she has the right method to acquire a new language. First, the important thing to do is to keep away from "traditional" "boring" methods. They all advise students to learn vocabulary but not "memorize" vocabulary.
All these international poliglots have something in common: they have no idea how the brain works. They are so immersed in learning languages they skip everything else, even reading, which they say is boring.
I have always thought that a language was a tool to open a culture, a history, a way of life, a literature. To me a new language is a challenge to research all that is behind the language of a people. We learn French to do business, to make new friends, to get in touch with its literature, to discover its gastronomy, to find out what makes the French tick and also what the French have contributed to European history and thought. A tall order indeed that requires time.
We cannot pile up language upon language. A passing, surface-knowledge of a language is ok to order a cup of coffee or ask for directions in Peking... but nothing else.
In my case, to keep up two languages is a full-time job which forces me to learn new things every day. But perhaps I have a second-rate brain, second, or third, to the brain polyglots have. But I have no way of knowing how deeply they know the tongues they claim to master.