You can see what Riot did here. They used to care about their players and really listen to what the gaming community thought. Now they just want to cover their own liability and cash in on their success. So much easier to ban people based on keyword trash rather than actually deal with the real toxic people or use adult judgement.
Riot does actually have real people who make the final decision as to whether or not someone gets punished. There's an automatic filter put in to sort through the probably 5 million+ reports they get on a daily basis, but the ones it passes on are each individually reviewed by a Rioter, specifically if more severe punishment is necessary, such as a permanent ban. The system may hand out chat restrictions or low priority queue, but a real Rioter will always be the one handing out any kind of account ban.
If you wanna manually sort through over 5mil reports daily, by all means.
