Magnus Carlsen [1] became the highest rated chess player in the world at 19. This means that either it is possible to master very complex subjects while young, or chess is not very complex.
I don't understand why people, including the author, are completely disregarding experience here. I agree with the author's points that a young person, even a teen, could bring a lot to the table and has his own qualities, one of which is not great experience. But that doesn't disqualify him for any job, given a hunger to learn and a passion for his work. But to suggest that "the only difference is in music taste"--well, if you measure any one young person against any one older one, you could get that result, but I'd be hard pressed to expect the same when comparing you with yourself 10 years down.
Here's something I learned: It takes years--several years--to come close to mastering anything of sufficient complexity to be worth mastering. That is just not possible when you're young. We've all had to deal with that.
"I fear not the man who has practiced 10,000 kicks once. But I fear the man who has practiced one kick 10,000 times."
Be water, my friend.