Why is Riot unwilling to make this game better for the average player?

After once again almost getting to promos and subsequently losing three games in a row for the final time I can only continue to wonder why Riot is not more vigilant about trolls and leavers. How is it possible you can have three ranked games in a row with someone that feeds two deaths and rage quits or someone that is the last pick in champ select and says "top or feed" and when a top is picked still picks a top and refuses to do anything else? Why are people like this allowed to play any more than a single game if reported? I know of many people who became disenfranchised with this game for the same reason and absolutely nothing has been done about it. It continues to happen. The oddest part about this whole thing is that most of us goes on 6 or so game win streaks when you get decent people that are willing to help team and hold their own. If this is the case why do they then find games to throw in a bunch of trolls and send you from 2 points away from promos back down to 14 points? Is it really so hard to weed these players out? The answer is obviously no, and the only reason is Riot's unwillingness to care about its core player base.

On top of this when you are not getting a troll you are instead getting a smurf on the other team who is "bringing a friend to plat or diamond". How are these players allowed to continue over and over again? Frankly I have dealt with it all for too long, tried to leave and come back, but its always the same thing that has ruined ranked and any chance of the average person getting better. There seems to be no improvement and while I am sure Riot will not be sad to see me go (maybe as I have put a decent amount of money into game trying to make it more interesting), they just do not care about the majority of their player base and the actual people that they make the most money from. That being the case I am finished with this game and will never play again. I suppose I am sad I wasted the money looking back on it, but we all make mistakes and learn from them, I hope Riot does the same for future interested players.