Why can't Riot just combine their new champ select with the successful Team Builder/Blind Pick?

I think all anyone wants/wanted was the option to do Team Builder while being able to select TWO champs/roles (to cut down on wait time). Basically what that does is make it a blind pick where you get to have a chance at being guaranteed what role you want...instead they strip away team builder and make this new champ select (where yes, you do get a guaranteed role) limited strictly to Draft Pick. Draft Pick takes too long, and for people that want to play more casual, fun games--it's not as fun to have the champ you want to play banned or to be counter picked. The length of it the major issue for me, because you can get to the very end of the process only to have someone dodge because they didn't lock in. They can have the champ selected, but merely by not LOCKING IN they restart the entire process.

I just can't wrap my head around why they thought the only queue that should guarantee players a specific role should be limited to draft. When this new "pick a primary and alternate role to queue as" would have worked just fine on Team Builder or Blind.