Smurfs are healthy for the new player experience because they give new players opponents to play against while they're levelling up. If new accounts were limited to playing against only new players, queue times would be absurdly long. Have you considered how long this game has been out? Most people making a new account, the **vast **majority, already have one at level 30.
If you remove all of those players, or segregate them from the new players, then it takes 10 times as long for them to find a game and that's far more discouraging than getting your ass kicked a few times as a newbie.
If you're truly interested only in winning then there are always bot games or even ARAMs for you to play as you level up. You don't have to play draft pick summoners rift.