Excellent post. As a self-taught frontend developer with not so much experience I value your question immensely. There is so much to learn, and short of going for a PHD in computational science, how can we learn all that there is to learn? Companies should not look to an individual employee to solve their intricate problems, but rather someone can become a valuable team player and eager to learn what's needed to understand their products.

I hope your friend found a much better opportunity than this company evaluating on one particular aspect. He is already a hero in my eyes, because he's come so far.