How accurate is the reporting system?
If anyone/everyone can honor/report anyone else, who's to say that information is accurate? If the "guy" having a bad day reports everyone after every game simply because he can and he's mad, and there so happens to be multiples of that "guy" reporting everyone, innocent people would receive warning boxes while they're queued up for another match. This could happen especially to someone who attempted to stick up for another person. I would hope this would be something Riot has thought of, considering I hear tales of new ways to punish toxicity. Or rather to exclude the people who exhibit "toxic behavior" from bonuses. See the attached links for the aforementioned story.