First, we remove dominion because "the playerbase wasn't high enough", instead of actually putting forth any effort or any attempts into balancing the mode. Now, we're removing Twisted Treeline. I havn't seen their stupid ass reasons why, but my guess it's the same exact reason, because the playerbase isn't where it needs to be.
I've hit Diamond 4 on TT last season, and I have to tell you, they're not wrong that the playerbase is so insignificant. Once you get that high in MMR, you can have bronze players on your team because there's like 40 people in Diamond on TT. The games are always completely one sided and don't really offer that much.
Of course, the map shouldn't be revolved over its ranked mode. Instead of just removing something completely, give it some love and attention.
_**(They havn't changed a single thing in the map since season 4, whether it be through balance, QOL or Items.)**_
i'm just waiting for them to remove ARAM because it's too random, because that's how fucking stupid Riots logic is right now.