I mean the whole point of Team builder is that you play what you want (LIKE IT SHOULD BE), and it's a normal queue, so... why are the 2 others queue still here? The Team builder queues would be much faster if all the normal players jsut go there, right?
So... why are those other 2 queues still there?
Blind pick is still there because people like to fill, Draft is still there because it's a more competitive environment to practice for ranked in (no mirror matchups, counterpicking, bans).
team builder does not even come close to replacing draft. yeah it fixes the most blind pick problems but blind pick people are do not want to "wait". They much rather fight over who said what first.
Also who said
play what you want (LIKE IT SHOULD BE)
cause they are stupid.
Bans.... bans are missing. That's half the fun :D. And riot has doubts and issues about this team builder mode, lets say you end up with 4 ranked diamond players in normal TB, and the only available supports are 3 players under lvl 15, should the system let them in your game or should you wait more, what if while you wait all those 3 are already placed in more level adequate teams.
Also this discourages trying new things, new champions and new builds , of meta picks etc. Coz here the creator has an option to ban you out if he doesent like your summoners even.
Here is an example:
I have been kicked out of 8 match ups in a row with Garen top with smite at a time when top-smite was just starting, when 
was giving 25% bonus HP, before people started making videos and posts about it, so at that time only couple people of people backed me up, one of them was a creator and he couldn't keep players in the team coz of me.
Then i got in to normal dogged once waited a bit and on the second try I got to play garen top with smite.
