LP loss and gain should be alterd based on your performance in the game.
Sometimes i do everything right and carry hard but still lose. And some times an enemy plays perfectly but still loses. In both scenarios that one person that still managed to take towers, have 200-300 cs, Secure objectives, and have a KDA of 29-3-18 and yet still lose he/she often ends up with an S or S+. So why not change the loss and gain of LP based on your performance. That way we can get a better idea of how good a person is at leugue.