Pehaps the points in this article don't translate to reality, but this article don't necessarily represent game design articles at large. But it does have a good amount of good points, it all depends on what game you make. This is not the be-all end-all of game design, it's one article, written by a journalist and not a designer.
Writing music and developing a game are two very different things, believe me I do both. One is about recognizing pitch and having a trained ear, muscle memory and dexterity. game design, not so much. Game design is a lot of theory: psychology, behaviorism, most importantly logic. All do translate well into articles and other written media.
Post-mortems are some of the most interesting articles I've ever read and there's tons of great information in them. Game design articles can contain great amounts of knowledge and tricks that you can learn of instead of running into the wall yourself and learning the hard way. There was a double fine "dev plays" episode featuring John Romero, it was amazingly interesting and I learned a great deal from it, you should def. take a look. I strongly disagree that you should not seek out prior knowledge, which is part of reading articles and consuming other kinds of similar media (video interviews with devs for example).
That said, no one expect to be able to perfectly master a skill just by reading about it. Articles are a good tool, a very good tool I might add and will most likely aid you as a developer more than hurt you. It's not a substitute for practice and no one suggested as such. I believe every developer should read as much as they can but be smart about what information is useful for their game. Information is never not useful, eventually. So absorb it all for future reference.