why lose lp to dodge feeders?

so, recently, i had someone in my match that was going to play , but there was this other person who was going mid lane who banned his . The got really pissed and said the person was retarded... the other guy said that he was high. After that, the one who was going to play chose and said that he was going to feed his lane, originally bringing , changing to . what I don't understand is why 1, people are so toxic and can only play one champ, especially in silver. And 2, why I am penalized by losing lp if I try to dodge because I am actually serious about the game... the dude could have just as easy went and not trolled. this is a problem I feel riot needs to change and therefore give us a choice to describe why we dodged and not penalize people like me because we dont deserve to have a free loss because of trolls or lose lp for avoiding them...