To address/explain some of your concerns
*Long arms: Climbing brands always have longgg arms on their jackets. I have monkey arms for my height, and my Rab, Arc, and EB jackets all have sleeves that extend to my first knuckle. They do this so that when you reach up or forward (or any other motion a climber would see, but a backpacker likely would not), the sleeves still cover your wrists. It's really a benefit more than anything
*Rerouting of cords inside the jacket, as opposed to outside: Yeah EB exclusively do this. In highwinds, if that cord were on the outside, it would be a whip, with your face being on the receiving end. A lil bit inconvenient for traditional uses…
*Material backed pockets: I'm only speculating here, but I'd imagine it's just for weather proofness and to stop drafts. E.g. You can stand around where your hands in your pockets for extra warmth, without compromising your core's temperature.
A lot of their gear is great for lightweight backpacking, but in the end its all climber oriented. THey have a very strict High Speed/Low Drag approach to their gear, eliminating most things that hang off/or flap around on a jacket. Most of the times it works, and is likely to because of guide input during the design process. Other times it doesn't. EB, and not the guides, gets the final say in what goes in or comes out of the product. Could be cost cutting, efficiency in production etc. I've read testimonies from some guides who helped design the products, be unsatisfied about the way the final product came out.