From today's Christina Kahrl chat, following up on an answer in which she badmouths Ryan Sweeney:

vegasbill (Las Vegas): UZR and BPro defense stats both have Sweeney as a pretty great defender. Combined with his average offense he's a valuable player.

Christina Kahrl: Average for what, all major league hitters? Certainly not for right fielders; a .261 EqA from a corner outfielder isn't valuable, it's something you have to overcome to score enough runs to contend.

How did one of the main Baseball Prospectus writers completely miss the boat on valuing defense and positional adjustments?