Ranked MMR thoughts

So as you win and your Mmr grows riot starts to stack less and less capable players on your team. Thus making climbing the ladder very difficult over time until you lose and the process starts over again a few steps back, like a revolving door. Problem is that the consequences for losing remains the same whether I go 20-9 and still can't carry doing all that I can or if I'm trolling and lose that way. I think riot needs to find a system that can reward individual excellence. Why punish the player that was literally carrying his team ?