I'm convinced it's DEFINITELY bots that fill in with random summoner names if a match hasn't been found in a while, like late at night. There's no other explanation for there are champs that just stand there and fight like Beginner bots. Also when there's an overwhelming lack of coordination with the team. There's also more complex instances like an Inhibitor turret that only needs 1 hit to get taken down, but the "teammate" is still just hitting minions back towards middle instead of running past them to help take down the turret, while ignoring pings and chat. Lapse in coordination or feedback of this nature from teammates is not an isolated instance either.
Maybe, but highly unlikely there more ppl who have chat and the map turned off in ARAM. And that don't care if we win or lose or how many times they die, but I don't believe this to be the case. Unskilled players and feeders tend to have a more "purposeful" pattern, or end up in the bushes at least once per game.
Either I'm crazy, or after +4 years of playing LoL, after recent patches Finding an ARAM match late at night after the 3:00 minute mark or so just automatically teams you up with really drunk players.