'lets the community rate what is considered unacceptable'

We have already seen how sensitive the playerbase is in this game, I rather not have this.

Stuff like discrimination however, well thats already against the TOS and can be reported and action can be taken if evidence is provided. I assume LoL are using it for this reason above else, if people are thinking it to be used for calling out players for making errors or low output etc.., this is not where it applies to or should.