Team builder is failing
Team builder was suppose to give the team an opportunity to try out something "new" (Yes, keep laughing.) and develope teams that YOU want instead of just what "you get." This is failing miserably, because I can't play Zyra mid without being kicked. And I can't play Sivir mid, top without getting kicked or having to wait literally 30 minutes. The fact that you are forced to play the meta in team builder, that was designed for more experimentation, is pretty disgusting.
I don't want to see the same 5 adc's play against the other adc that is always Vayne. And I don't always want to see the same 5 champions in the top lane, and I don't want to see the same 5 champions in the mid lane. If I'm lucky, somebody is playing TF jungle for devour, because THAT'S FUN NAMIEAN!?
Nobody wants to wait 45 minutes for a support to finally get picked, but then they leave instantly because supports and marksman get games every 3 seconds. Vise versa as well, both of those roles do that because nobody wants to play those roles. If you play support, and you main a support, Riot will indefinitely nerf your champion, unless if you are Thresh or Bard. Bard, because, well, who the hell would nerf Bard? If you play marksman and you didn't pick Vayne, there is a 90% chance that you are going up against a Vayne. Because SURPRISE! I'm back. 
These are all problems with the balancing team. If I had the balancing team we had right now, try to balance out my toxicity compared to my passive aggressive happiness I show in my games, I would be banned by the end of the week. If the banning system worked. (LOL) If I let the balancing team try to fix my paper cut finger, I would end up with either no finger or a mutilated finger. Literally, you could have just used a BAND-AID!
TL;DR: Team builder is failing because of the balancing team and because Riot feels it is very much necessary to force the meta down our throats.
**Continues to sit in team builder lobby, waiting to play **
I think the main reason of your problems is that TB is used to practice roles people don't usually get in the other modes.And not much for unusual picks and roles.I think your only option is either round up a group of friends that will let you pick anything you want or get used to the long que times.And this is very important don't act like a hypocrite if you get another unusual pick in your team.Like the Thresh ADC i got once that kept bitching about me being Mundo and having no lane pressure or shit like that.