Why can people leave ranked games and get virtually no punishment?

I've been playing league of about a year now and I know that you sometimes need to leave a game or maybe your connection is causing a problem and I understand it happening every now and then but 6 out of 20 of my ranked games I've had someone with connection problems, someone who dced or someone who afked in spawn. My problem is that we get punished almost as much by this because it's almost impossible to win when this happens. I understand that we can't lose less LP since that could be every easily abused, but why don't people who dc in a ranked game lose more LP or lose honor levels? Why do the people who dc only lose a bit of their time and just as much LP the people who stayed and had to play it out? I feel like people who leave ranked game should have more of a punishment than start q and wait 20 mins while doing something else; that way people think more about how much time they have before they start a game.