The point is that you're not supposed to attempt to play League knowing there is a good chance you'll disconnect. Whether that be a poor Internet connection, bad wiring, a computer prone to overheating, etc.
There are 9 other players in that game, and anything short of a completely unpredictable emergency is not going to make them feel any better about losing the opportunity to have a competitive game.
If it's in any way within your ability to repair, predict, or even suspect any game-interrupting event that may occur, it's your responsibility to other players not to expose them to any unreasonable or unnecessary risk.
House is on fire? No problem, run for your life. Sudden family emergency? No one can fault you for that. But you know perfectly well the wiring in your house is of poor quality. It is entirely within your control to get it fixed, or if that is not possible, to not play League. It may not seem fair to you, but it's just as unfair to the other players that experience the side-effects of your problems.