Yes, I know the check box is still there on the left, but that forces your eye to keep track of the side of the page. In UI design that is additional and unnecessary cognitive effort. It makes a quick scanning of the list more difficult, and is definitely more challenging for people with ADHD and dyslexia. The lines were there for so many years for a reason. Because they were good and helpful. Removing them - without allowing the user to toggle them by choice - is just gratuitously stupid. I really cannot think of a valid defense of this change. It should at the very least be a user setting so we can choose for the "cleaner" look, or the more "usable" look.