I had a 4-premade once where their Morgana was my support (I never asked for it, they just did so by themselves) and she did nothing. Literally NOTHING but running around. In the first 10 minutes or so she tried to snare 2 times and just ran into the enemies, but claimed she is trying and not feeding. I asked who's premade with her and the rest of the guys responded. I asked why they are not teaching her, they just replied I should shut up, she is new and I am reported. Of course nothing happens to me, but she fed the game like crazy, ending with with 0/8/2 or something in a game with 30 kills. Being new and being retarded are two different things, and that is the problem in my opinion. RIOT should (and I am sure they do) consider kill participation too. Of course only over a long run, but the system need to get to know who is potentially being a feeder. If you are Level 15 and still do not use your abilities and run into the enemies like that, you are not just a normal "feeder". I can't remember in any game that I kept running into enemy projectiles and claimed I am new. This has to stop. If you constantly end 0/8/2, either you are a feeder your the matchmaking sucks because it can't put you in games suited to your skills.
I have an Excel sheet running on both my mains, Bard and Ashe, and with my 116 Bard games I have not reached 2-digit death counters. As Ashe I reached it 1 time (10 deaths, game 40) in 82 games played. So no, you don't have to reach those digits at all if you are a bit smart...
I also report anyone with a KDA that is too off. I mean, you can easily earn assits and thus you can feed 0/10/10 and I would not touch the red excalamation mark. Because that would be solid. But this 1/12/1 "I am new to da gameeee" but keeps running into the enemy by doing stupid things and not blatantly feeding is also unbearable and basically the same end result.