AFK kicker isn't the solution. you just have to make the server capable to handling that much volumne.
best solution to traffic is making the highway bigger, not banning people from using the highway.

during the 10 some years I played FF11 I never seen this kind of problem, not to mention FF11 servers hosts both JP/NA players and anyone who been to Jeuno during peak hours would know what I am talking about.

not sure if SE cheaped out on server or what because the miserble failure of FF14 v1.0, but not able to handle the initial comeback volumne is not helping the game either.

a mmo that kicks afk player out just because the server can't handle the volumne won't get anywhere. you are going to have people complain about gil farmer that takes up all the server slots later.