Latency problems are usually akin to higher ping, not disconnected from games entirely. My proposed solution would only penalize people if games end (or could end) with a 4 man (or less) surrender vote. Thats first.
Second, I agree that bots are annoying, but I don't take this stance in normal games. Normal games are practice and while you are still inconveniencing 4 members of your team, at least you aren't negatively affecting their ability to climb; more to the point, there is no lasting impact of your disconnect on a normal game. I would still report a person in a normal game for afking, but whether I lose or win the normal game is less important than a ranked one. Hence why I have no real desire (or motivation, as my suggestion shows) to try to fix normals, only ranked.
Also, generally speaking, latency issues do not randomly show up and go away between games. Latency is affected by your internet setup (predominately). If your internet setup remains the same with no changes, your latency will not change either. Multiple people on a network, downloading while playing, etc are things that would cause latency and while the player may not have control over what other members of their household do, it does bring us to the question of responsibility. It is irresponsible and rude to queue up for a ranked game if you know you have problems with latency, or will have problems at certain times of day.
Now, its pretty clear that the majority of the people playing league of legends are responsible, seeing as how afk's aren't the most common occurrence. Because the vast majority of players never disconnect from games, this change wouldn't affect these players. It will really only affect the people that do disconnect frequently; and regardless of reason, these people should be getting penalized (and their teammates should not).
As one of the players that doesn't disconnect from games, I know that I can say (with certainty) that I would be willing to run the "risk" of getting a -60 to lp for a disconnect if it means the number of disconnects I get in my games goes down. The way I see it, any player who is being responsible about queuing for ranked wouldn't have a problem with this.
Now, of course you can bring up the situation where someone who never quits has to quit a game for whatever reason, and you could claim that its unfair for them to receive the penalty. I would disagree, and again, if they are a responsible player, they will accept the penalty knowing they screwed up a game for the other 4 members of the team.
And that, to me, strikes the heart of the matter; its about taking responsibility for your actions, regardless of whether or not you meant for them to occur. Its not a matter of black and while and grey areas, because at the end of the day, regardless of what caused it, an afk causes 4 innocent people to lose a game. My proposal puts that responsibility on each player queuing for a game; moral of the story is if you don't know if you will be able to complete a ranked game, don't queue. And if you do, accept whatever outcome occurs as a result of your actions.