The word "clutch" doesn't appear in that article once. Obviously you give more weight to framing with 2 strikes because it results in a strikeout, the best possible outcome for a pitcher. How is this hard to understand?
For example, Navarro constantly botches 2 strike breaking pitches in the zone, which means the pitcher not only doesn't get the strike out, but he also has to throw more pitches and has an extra ball in the count.