The people who say the current system is flawed are almost always extremely toxic here or try to troll, and most have a consistent history of being punished by the system. It's not that the system isn't working, it's that they don't agree with it and are loud about it.
The Tribunal "voting" should be coming back this year. They were able to give it low priority because of the efficiency of the automated Instant Feedback system, and they needed to put most of their resources into the new Champ Select. With the Champ Select going live in 6.1 they will be able to put more people back on the Player Behavior Initiative, which includes Tribunal Voting and the Honor system.
If you have more questions about the player behavior systems, a great source of information is Lyte's ask.fm (though he's been on vacation/busy the past month).
https://ask.fm/RiotLyte/answers/134200448962
https://ask.fm/RiotLyte/answers/134527663810
https://ask.fm/RiotLyte/answers/134415323842