When I used to play Maze Runner when MCPVP was still alive, I was pretty much really good at the game since I played it non-stop for two or more weeks. Because of that, I can mostly predict what would happen in the beginning of a day/round of Maze Runner.
So I was playing Maze Runner one day, and my whole team was...well...pretty much annoying. They kept putting the princess (a "character" that's important in the game because if she dies, the whole team basically dies) in the most open area of our base, saying they know what they are doing. I'm not even sure if they were trolling or being serious. Either way, it was annoying as heck.
When the gates of our base finally open, I have always had the habit of carrying the princess with me while going out in the maze because every time. Yes. EVERY TIME I leave the princess in the base, everyone just leaves the princess by herself and goes out looting for chests in the maze, leaving the princess dead-open to other enemy teams that can come in. I've always bring the princess with me with no problems whatsoever.
When my (good?) habit gets to me, I carried the princess with me to the maze. We told each other that one of each of us would go out to one gate and one would guard (there are four gates and five of us). Most of us listened, but then the player who was supposed to guard decided to follow me because I had the princess, when in reality, he just wanted to steal the loot I found (I was also going to share it with my teammates when I'm done in the maze). When I found my suspicions were right, I decided to just lose him in the maze. It worked, and I worked myself back to base, since it was almost night time.
When I was about to get back to base, an enemy team was already in our base. As predicted. I just stayed in the maze at night which I was okay with because on the first night there's rarely any grievers coming to kill me. Then, while I was waiting for day to come back, one of my teammates forgot to type "/" for "/message <player> <message>" which was probably the worst mistake to ever do in this game. He messaged a member of the enemy team if they got the coordinates to our team base and if they are there. That was the last straw. I just left the game, not caring whether I win or lose (because I used to get really upset when my team loses).
TL;DR: Teammates on my team in a game were just being trolls and betraying each other which is why I don't play Maze Runner anymore. Especially on the other server that MCPVP decided to give it to because the people there were much worse.