Autofill lessens win rate

Over the past few game I've played of ranked, I've had to auto-fill quite a bit of them and I've started to see my mmr drop because of it. My real question is why make some one play a position they don't want, this game is suppose to be a fun game an I've seen none of that when I auto-fill every time. Also the people who waited in queue time for their position wanted to play that specific role because they waited for it, if I want to play only two sets of roles, let me wait longer and play those two sets of roles instead of making my experience poor and waste my time. Please get rid of the auto-fill there is no point for it, the system that was implemented before was perfectly fine the way it was.