There needs to be a permanent kills-matter-most game mode
There should be a game mode for players who don't like objective-based games. That way all the rest of the players don't have to sit through having allies who don't attack turrets but prioritize getting and stealing kills. One prime example would be the assassin jungler who gets twenty kills but 0 towers and 0 assists-- then blames their allies for the lost.
So for those players-- or for anyone who just wants to kill without worrying about turrets from time to time-- there needs to be an arena-like game mode where kills are either the only things that matter, or the things that matter most.
Edit: Ascension is the closest, but due to the nature of the altars being worth more points than any kill it's far easier to win by getting them than kills--even as the Ascended. It's a fight-heavy mode where prioritizing a separate objective is still better than kills.