How I became a polyglot and why it was not worth it

The beginning of the journey
Back in the end of 2011, I happened to find Michel Thomas Portuguese course by chance.
After a week of daily one or two-hour learning sessions, I was able to hold on a conversation with my internet friends from Portugal and Brazil.
His method inspired me to dive into other foreign languages. I took almost all the courses this method offered and then started experimenting with the other languages beyond the course. Within 2 years I reached more or less advanced level in 10 languages and grasped some basics in another 7.
During this time I visited 4 countries and was even more inspired by these trips, because I could communicate with the locals which kept on persuading me that I spoke their language very well.
The end of the journey
But unexpectedly, I faced the reality after I moved to Brazil in the beginning of 2015.
What happened?
I found the job at the Chinese company and the first thing that appeared to be the problem was my Portuguese: I had a strong accent and I made mistakes in grammar. Yet my colleagues assured me that my Portuguese was perfect for the time I spent in Brazil at that moment: 3 months. But when I asked them if somebody would hire me to work at sales or at a call-center, everyone said no.
The same thing was with my Chinese: I was good at understanding films and chatting about politics and leisure, but when it came to translating a conference call in between two engineers about accessories defects and other related problems I felt screwed for the first time.
After these two cases, I realized that the level of the other foreign languages is almost the same as these two.
Solution:
I decided to give up (at least temporarily) the other 7 languages I know. Neither Indonesian nor Turkish are worthy in the Brazilian market as well as the other set of languages I used to learn.
When I have a spare time and a companion to talk to, I try to talk about professional topics or hobbies that a person is passionate about. Before that I ask to correct myself when I am wrong.
In the public transport, during a commute, I listen to audiobooks or profession-related podcasts.
Conclusion:
Because of this fast-learning-methods experience, I learned how to learn fast, whatever a skill is.
Now it is time to polish the skill.
Is it worth becoming a polyglot?
In my case: no, it´s not
If you want a language to become your trade, I think, you should really focus on a specific language and master it.