There needs to be serious disincentive to this detestable gaming practice. Players have reported this since the bounty free Ladder was instigated. That's how long players take advantage of others using bad game mechanic changes by HCS. Before the change players regulated this practice with their own effort to drop the offending cheat the full 5!
I think two things should change post haste under the Ladder system. First, if the player leaves after hitting any player on the Ladder, ALL attacks on ALL players should become instantly bountyable for 72 hours(longer then the typical 48). Second, the attacking player should have a 1 month cooldown from re-entering the Ladder.
Both of these disincentives would prevent this abhorrent practice, while simultaneously retaining an option for an outmatched player to use the chicken exit on the Ladder. Come on Hoof!!