Ranked and MMR

Can i just talk about how the system works now and why is it that so many people are stuck in tier's that they might not deserve or are stuck in because of inconsistency in the system? Maybe it's just me but I feel like my climb was more or less undeserved because now I am forced to play more games than I should even need in order to hit the next tier, why is my MMR so bad after winning more than half my games?