If we don't use grades, then what else will we use? Yeah, I get that a load of folks are all "rah rah!" about getting rid of 'useless' greats and switching over to detailed and personal feedback, but you can't objectively compare that kind of feedback.
Not to mention, it's kinda ridiculous to expect a teacher to provide custom feedback to each one of his 130+ students when in all honesty, only 10 of them (and maybe a single parent) will ever read them and take the feedback to heart. As a high school teacher, I already spend a ton of time on just schoolwork, lesson planning, grading, etc. I don't have the time nor the capacity to provide specialized feedback to each and every one of my students. If not grades, then what can we use?