Wow... you people seriously think there are that many griefers in this game... seems pretty cynical.
The only time I've seen anyone really go afk was before concede was implemented so that we could destroy their base more quickly when we had clearly won. Seemed fair enough to me. The problem with doing this is, unlike concede, you can go afk even if you're teammate isn't on-board that you've lost for sure yet. But meh; if one person on your team is basically going to concede, you've probably lost anyway. It's been argued there is little hope for a comeback in this kind of game. It reminds me of chess when you're down a queen, two rooks, and two bishops.... yeah it's possible you could get a freak checkmate, but most likely you're a goner.
My complaints are with the people abusing the system - who go AFK to avoid having to use the concede option, or who go AFK merely to gain more favour points (any system where you earn something merely from being in a game is going to be abused in this way).
I don't get this at all. Why would someone go AFK to avoid having to use the concede option? The only thing I can think of is that they don't know about concede, but you're arguing that they're really still at their keyboard, so when the other team is in a bad situation I remind them that F10 is concede. Going AFK to earn more favor points? Again, 1.) Favor points don't matter for shit and 2.) don't you get just as many favor points from conceding as losing? This line of reasoning really makes no sense to me.
Now, some people have mentioned going pseudo-AFK is really for griefing. Seems pretty meh to me. If they're still at the keyboard (so my idle-kick wouldn't kick in) a far better way to grief would be to continually suicide to the other team. Or they could still just rage quit; many would argue the AI-feeding would be worse than being AFK at the crystal anyway. So not really sure I buy the griefing argument anyway, but bans and kick-votes could help out there.