In my opinion, team-builder was one of the most "expensive" and non-lucrative projects by Riot
1st of all, before you read this, I want to state that this is just my pure opinion and have no will of QQing or raging against Riot because of aiming some projects and not going to others. While I don't agree with many of their decisions, I'm just a normal player and I have to respect their hard-working and effort they do on this.
Now onto topic:
With all due respect Lyte, you spent so much effort and server resources to put this on servers and I really believe that a new map like Magma would have way much more use than this mode. I mean really, I don't have the data, but I'm almost sure that other modes were used more per day.
In my humble opinion (and not trying to be rude in anyway, just stating my pure opinion) this mode was the worse thing Riot ever made. So few people use it, it lacks polishing, it appears that takes a lot of server resources and staff resources...
If you don't improve this mode at all I see no point of using it. And I don't mean to QQ for URF or etc, because it wasn't really my thing, it was fun for some days but not forever, I get it. But even URF was so much better than this mode.
I really believe you should try to have more feedback from your players before going onto new projects. I understand they take a lot of effort and many appear so damn nice, but theory isn't the same as pratic.
And pls, give the same effort you did to this project (teambuilder) for EU-tribunal and improving control on player behaviour. In my opinion, that is way more important and many players (specially EU) are struggling with the current environment on the game. I want to have fun, not to have bad experiences with rage and insulting.