Main problem is the AFK system would not completely clear the 1017 errors, as someone already said. If you kick a hand full of afk people, then a hand full of players would get in, yet there are thousands of players wanting to play they'd get 1017 as well.
Adding more hardware is a better fix than the afk system... if it is needed, after they finish testing the new hardware/servers/worlds then they will add it.
And being honest, knowing people looking at the loopholes, people would just create macros to cast a skill every X time to avoid being kicked with the AFK system. Sorry if this gave people ideas, but it would happen sooner or later.
That's what people do in GW2 when in World vs World when it is 99.9% of the time full.
