In my opinion this abuse should stay in the game to a degree. A few serverhops can really help a player out if he is really unlucky or caught in a dangerous situation and values surviving more than the immersion in the game. Especially now in a phase of the game where all of my top geared characters were randomly deleted upon joining a server, and loot does not respawn the normal way.
The question is though: how to prevent abusers from profit too much from a "panic button"
I really like the idea of teleporting players out of cities upon server joining. Maybe leaving a server shortly after shooting with a weapon can result in a 3 minute timeout. Or after leaving a server your character remains for a minute to be killed by players only or be looted.