I'm trying to grasp this report system

I've been through virtually every elo, from Bronze V-diamond III currently plat II and you get different types of people that ruin games, but what kind of person I can't stand is the dude that just straight up ints. The guy that swears up and down can just be /muted, but you can't /unint your teammate. I can handle losing a game if we just all get stomped or they just our team fought us, there's nothing you can do about that and you can't really get upset with your team. but why does the guy that says to go f yourself or something trivial like kys get a higher ban priority than an inter? I've had dudes that'll int and say "good luck I won't get banned" and I quote them and report them and nothing happens. I just can't wrap my head around why words get more power over action?