Riot grading system places WAY too much emphasis on CS

CS/Farm is an important and valuable player skill: it helps you get the gold you need to buy items and win the game. That being said, it's important because it's a means to an end: taking objectives, defeating enemy champions, and destroying the nexus. The fact that it makes up the majority of your score has always seemed off to me. If you're achieving the main goals with middling farm, to my mind that's better than not achieving any other goals but having perfect farm.

My last game provided a good example (to me): as Udyr, I scored 9/1/10, 3 out of 4 dragons, rift herald, and 3 towers. My vision score was well ahead of everyone including both supports. However, because my farm was mediocre I got an A-. So according to Riot, this was a subpar performance. I would definitely have gotten a better score if I had spent the entire time in the jungle farming (and warding). Is that really the kind of play we want to reward?