The Champion Mastery system makes me sad

When you queue up as Support and pretty much NEVER hang around on bot lane in a normal game because you're busy bullying the enemy jungler, that doesn't warrant an S rank, not even a B rank. My Twitch was 0/3, god knows why he didn't wish cancer on me because I ruined his entire early game by not being there for him. I took out their Bard once in a while and mainly focused on annoying Graves, but because the Champion Mastery system focuses so heavily on the numbers and NOT on the teamwork, I get an S- for performance.

All that by playing 'Support' Shaco, never providing sight, never helping my ADC, always roaming and bullying Graves & Nasus. I wish that system cared more about teamwork and 'doing your job' (especially for Supports. If you don't actually help your team and only play for the K/D/A and fun, no peel, no assisting, you don't deserve an S rank.) than it does right now. I could deny my own ADC farm every two seconds and steal his entire income just by putting dolls all over the lane, and the system would reward me for doing so because I farmed a lot. That I completely messed up my ADC's game doesn't seem to have any importance whatsoever.