Why leavers don't get punished

To start, I've been having a LOT (high%) of games with leavers recently. Now with that out of the way; I've reported some serious bad-eggs before, received messages saying that a player I reported has been punished. However, I've literally never seen someone have any back-lash for leaving a game, rage quitting etc and it made me think "Why is that?"

Honestly, in my opinion, leaving a game is the worst thing you can do aside from running into the tower and feeding type thing. Think about it, someone can talk shit in chat all they want, you can mute them, and you can still win/play the game, but if someone leaves, its a 99.9% chance loss. 4 players lose the game, and the other 5 players are denied satisfaction that they won fair and square.

So, why are leavers so easily forgiven? Well it got me thinking; It's all about plausible deniability. I mean, think about it: real life happens. Sometimes you get DC'd and can't reconnect, the power goes out, someone shows up at your house unannounced, your cats on fire. So when a player leaves, the leave is taken as "the player had no choice but to leave": We don't know the reason WHY they left, but we've got to give them the benefit of the doubt. Innocent until proven guilty right?

"We here at Riot don't want to be the bad guys and demonize or punish our loyal players when the situation was out of their hands, so, feel free to leave the game whenever you don't feel like playing anymore. As long as you don't leave too many in a row or '2 many/10'- we totally understand."

So my issue is this; I'm going to give a scenario: let's say league had a total player base of 10 players, so every game of league had the same 10 people playing each match. IF a player could leave once every 50 games without a punishment, that would seem pretty reasonable right? But now what if EACH of the 10 players took that liberty to leave one in 50 games. We'll say that 50 total games were played and each player took their one liberty to leave one game each. 10/50 (or 20%) those games would be 4v5's.

I don't know about you, but having 20% of games be 4 v 5's seems pretty damn high to me. I'm NOT saying that's what the leave rate ACTUALLY IS. (I'm sure it's lower than that for ranked at least.) But I'm saying: even allowing players to leave as often as 1 in 50 games could potentially make that the case (it's sure felt like that to me in my recent games lol) Especially for normal games because players KNOW they can get away with leaving, and it's not like they are losing LP, so who the fuck cares right?

To sum up: Can something be done about leavers? Or can their be something to promote people not leaving games: rewards etc? Maybe a badge or something like this:

<[{V}]> Virtuous Badge: This player has played 50 games in a row without leaving and receives: 10% increased IP and 10% increased Key fragment drop rate.

The only thing that would have to be done is if Riot could make a system that "Shows them" if you are trying to reconnect to a game when the problem is on their part.