Let me try to help you here..
First and foremost. It is NOT Riot's responsibility to change the people who use their product. It is their job as a company to protect the assets that allow their company to thrive. And rightly so. Creating, developing and maintaining the player behavior system is a means to do that. It is their hope that in doing this they aren't simply eliminating players from their community but hoping to help some of those players understand that the game is there to be enjoyed by everyone and their actions aren't appreciated by the rest of the community. They're being very nice in this regard and although there isn't a perfect system, it's a very good system compared to what could be done.
There is a lot of negative behavior and more so at certain levels of the game than others. There's really only one way to deal with them. Report. By submitting positive reports against these players they can be addressed. League is a game of millions of people. Just because 1 guy in ONE of your games was a dick doesn't mean RIOT is capable of looking into it. It would take hundreds of employees to do this and it's simply not a feasible solution. They created the tribunal as a method of self policing and with the intent that if the goal is to find out what the community doesn't like then have the community issue the verdicts in each case and then create a program and system that allows us to easily report and penalize players that act against the majority themes that the community addressed in the Tribunal. Seems fair to me. Can it be accelerated? Can it be improved? Sure, but it takes more feedback and more time. This isn't magic. RIOT needs statistically relevant input to address concerns and then time to implement them.
Lastly, nothing illegal is being done here. They specifically explain the rules to you via ToU and other documentation. They then explain that they're essentially a membership to a private club and what they say goes. If you don't like that then you know where the door is located. Nothing's unfair, nothing is deceptive or illegal. It's been designed to be as fair as possible. You want change? Demands simply don't work. You aren't a union. You're not gonna rock management on their decision making when they're making the right calls, aren't seeing a dip in profit due to their actions and you represent an extreme minority.
Hope this helped. If you don't agree, I don't care. Your disagreement is purely a delusion.