it all boils down to one thing
if you save people who have proven to be a liability and they continue to be one.
you're asking for trouble. true to get rid of everyone of any threat level would mean you could be alone but you'd be safer and alive and in the long run better off
imo anyone trying to justify saving ben is kidding themselves and therefore won't survive long.
as for kenny true he's had his moments but in the key difference between kenny and ben is kenny actually thinks before acting even it if was one direction his family then the boat.
nice way to 'try and win' a debate by shifting blame on to another character..
by the same logic, lee has killed 'danny and or andy' or caused the death of mark by suggesting they go to the farm. in that case it was an unforeseen consequence. but ben was oblivious to the obvious dangers of his actions. which isn't the same as he chose to ignore.