The punishment MUST fit the crime.
Just being honest. Riot gives pretty extreme punishments. Like, I had no idea that these people were dropping from honor 5 to zero on the first offense.
Think about it. If your punishment snatches all their progress in one swoop, you're pushing League towards more toxicity. Its already hard to get honor as a genuinely good player, so when you take the bad players progress and say "redeem" yourself," what you may as well say is "be better at being toxic next time." because that's what has been happening.
Put yourselves in the shoes of an honor 3,4, or 5 player who argued with someone and took it way too far... That person, literally, loses everything. To lose so much in one go makes redeeming yourself feel pointless. So, metaphorically, that person might not ever say another bad word in games again, but now they're highly likely to wait out bad games, troll more without saying anything, and tilt other people in the process because they know that they're not getting that progress back anytime soon. Think about it, Riot.
If this persons goal was to get their honor back, why would this person really want to try hard in a normal they're not doing well in? I'm being serious. If that person isn't the best on their team, then they probably know full well that the game they're in has no value... In a realistic setting what do you think this person chooses to do? It's simple. If the game yields no value, then they obviously want it over as quickly as possible,so they wait it out. They pretend to care, they bait their allies, they don't join fights, and they say nothing the entire time. As a bonus, they can indirectly get one of their allies banned if they happen to catch on to what they're doing and say enough bad words towards them. To this person, it's the perfect punishment for wasting their time. And it can apply to anything. All they have to do is be smart enough to not tell you they're trolling and avoid a stupid score like 0/15/0.
In other words, "bad" players being unable to redeem themselves pushes them to give up being better players and focus their energy on being being better at being bad... Or they simply quit. Is there any wonder the games now feel more toxic? Real talk, If they feel they cant acquire the honors or satisfy themselves with a win, they put the effort into moving to the next game as soon as possible.