+1, I like your catch that the article is similar to Scott Adam’s Book’s advice. I liked the article, but I am biased since in my career I have tried very hard to be an expert at three things: classic symbolic AI, building large scale distributed systems, and Machine Learning.

I am in my mid 60s so I have had the benefit of working with many people who were individually very skilled in more that one field, and these people were the highest producers not just for the direct work they did but also for influencing other developers. These 7 or 8 people have had the greatest influence on my career.