If you want a tl;dr of the article, take the last bit: Both approaches have their merits and their failings. How about we focus on that instead of which system

If you want a tl;dr of the article, take the last bit: Both approaches have their merits and their failings. How about we focus on that instead of which system is open or closed? What is he referring to when he says "both approaches"? He's talking about open versus closed.