Going by the title of the post, I initially assumed the author was making a case for learning in a school/university-based environment, as opposed to autodidacticism ("self-learning"). This turned out to be wrong; rather, he is basically saying that any amount of studying (theory) does not make up for experience (practice).
The real title should be: "Theory without practice is overrated".
It's not even that. His assertion seems to be that practice outside of a sufficiently business-like environment doesn't count, because you won't be compelled to focus all of your time and energy on just those things that bring a positive change in rate of value production now. It's a dangerous game to play, but a desirable one moment-to-moment in an environment that severely dislikes disruptive ideas -- the thing that learning for something other than instant gratification is bound to cause.
The person he's quoting tells the opposite: practice without theory won't get you far in any comp.sci heavy field, which is true, but doesn't have anything to do with being self-taught.
