Most of the comments here are completely missing the point of the article.
The article is not about whether the ideas espoused by old philosophers are worth learning about, or about whether old philosophers are worth reading. The article asks the question of why philosophers prefer to read the original works of old philosophers, instead of reading descriptions of these ideas by authors who have demonstrated competence is explaining philosophical ideas. Which is the way that education is handled in most (all?) scientific fields.
The article is not about whether the ideas espoused by old philosophers are worth learning about, or about whether old philosophers are worth reading. The article asks the question of why philosophers prefer to read the original works of old philosophers, instead of reading descriptions of these ideas by authors who have demonstrated competence is explaining philosophical ideas. Which is the way that education is handled in most (all?) scientific fields.