I respectfully disagree with the idea of removing rewards for ranked match losses, since it also would make a match a waste of time for the players who put much effort from the losing team. What would I propose is the idea of rewarding players in terms of effort done, like killing x amount of players in a game, reviving x amount of downed players, decapping/capping x amount of nodes, healing teammates this x amount, etc., all of these disregarding whether your team loses or wins and the winning pips would just be a bonus. Not only it may discourage the AFKing in a matchup, but also could encourage the losing team at a moment to fight to the last to maybe turn the tides into their favor.
I don't know if Anet does this, but I think it would be great for them to have an active moderating team spectating in each matchups. In that way, if they receive reports of a player idling, then they could check the player in their match to see the AFKing for themselves and therefore do the appropriate actions for these players.