i saw a ton of loopers today, in the lowbie zones, and lots of corpses, with their lone boxes mourning the dead.
most people can't scramble together a half decent macro that runs for longer than 10 minutes without getting them killed, because this system is so simplistic, you have no real options and zero failsafe.
i suspect what you encountered were bots. adrenaline lets you bot 24/7 without fail. no death, no getting stuck, no downtimes while waiting for respawn, no running across the continent.
the loop macros are harmless in comparison. you can't really be completely afk for long, unless you bring a party to kill solo mobs... which is actually happening, but that's on the known issues list (running more than 3 clients).