I don't see these are in conflict at all. Both talk about spending the long period of time needed to attain Mastery. Mastering concepts is essential but mastering your way of working so as to maximize your productivity and the effectiveness of your practice is equally important. You do not want to be a dilettante who knows everything but produces nothing of substance or value.

I wrote a book specifically on how to go from good to great or at least how to become the best you can be... targeted to developers in the first 5 or maybe even 10 years of their career.

Level Up! How to Become a Great Professional Software Developer

https://leanpub.com/level_up

None of it has to do with any specific language or platform. The techniques I describe are not the only way to do it but I guarantee if you take at least some of them to heart, you will improve a great deal. I do espouse going deep on at least one platform or stack for at least several years. You might even get so formal as to build a competency map to track your progress. Much of what you learn is transferrable. 10 years or 10,000 hours will get you there no matter what but following the techniques I describe will get you there faster.

Steven Talcott Smith, Master Developer, Chief Happiness Officer, ÆLOGICA

http://aelogica.com | Great Rails teams for hire

http://appexpress.io | Rapid Application Development