So what do you want done about it? It is pretty harsh when compared to the other punishment as their first offense is a 14 day ban, after that is a permaban for anything they do wrong, be it intentionally feeding/trolling/toxic behavior/etc. that seems pretty harsh to me. You also dont want it to be too harsh because what about false positives? what if the system finds innocent people. Remember this isnt by any means a perfect system and people do get wrongfully punished. By your logic they shouldnt have a say in that because in your eyes they are rightfully being punished.
With that said I do wish they were much more faster. Because the longer they keep letting people get away with trolling/feeding the faster those types of people will keep up making new ideas to try and beat the system. Riot needs to always be two steps ahead of the game in cases like this. They do pretty well with 3rd party program bans. Again people still get wrongfully ban, but they seem to be banning them regularly as loads of people come here to complain about being ban that way. If they can do that with trolls/feeders i think the game could be better off.
If anything they just need to start working on the new Tribunal in full force. Let us get involved to help the large amount of the player base. Assuming the people they chose to be in the Tribunal im sure most will take it serious and actually help root out the bad people who play this game.