SHOULD WE CHANGE THE GRADE SYSTEM? (AKA a Tryhard Ranting About Why He Can't Get Above an A+ as Zac)

I'm not gonna lie, the grading system is messed up. Once, I got an S+ as support getting 9/4/20, and basically just helping out my ADC and doing nothing else. Of course, when I go jungle, ganking every lane, I get an A for 11/4/28, getting mid and bot absolutely fed, and winning the game 64/29... later, as AGAIN, I get an A+ for 8/2/6 and 20 less farm. That's when I realized it... there are 2 types of champs who can get S+: Assassin mid-laners (Eg. Talon, Zed, Yasuo, Katarina, ect.) and supports ( .) Plus, the ONLY people I see getting S+ on a loss is supports. There was a period of time when I could consistently get good grades as Bard, and all I could think was "wow, I must be going against really bad players." But then, I started getting into support Poppy. Despite completely maining Poppy top lane, I was rarely able to get S- or higher with her. However, my FIRST GAME as Poppy support got me an S+. MY FIRST GAME. I dunno, maybe I'm just awful at CSing and that's why my grades suck outside of Supp. But still, I'm able to get good grades as jungle, even with not-so-good K/D/A's.

So... what's my point? My point is, I think we've all been graded unfairly. I've seen adc's go 30/3/10, and not even get an S-... because the Supp gets it.

Please--what's YOUR opinion on the grading system? What's the worst the grading system ever screwed you over? Please comment with your opinions!