Bots are so obvious, Blizzard just needs a couple GMs to float around in BGs to ban them all!
There’s a few problems here. First off, Blizzard really dislikes the “looks like a bot” argument, because there are players that do somehow act goofy or derpy enough that people call bot on them. Actually, players will really call bot on any player doing anything remotely out of the ordinary (I got called a bot in TBC for farming Mageweave Cloth from low level ogres… There just wasn’t any on the AH, man!) Blizzard prefers something more concrete, and less circumstantial. But let’s say they did plop a GM or two into BGs to ban bots. Congrats, they’ve banned a bunch of bots, but this is very, very short-term. Bots will always be back, and if doing BGs gets them banned, they’ll just move elsewhere where they won’t be noticed.
This also brings up an issue called the “treadmill problem.” The treadmill problem basically refers to a task that doesn’t end, and therefore occupies someone infinitely because it has endless upkeep. Assuming the bots decided to not move and kept on doing BGs, someone is now doomed to sitting around, banning bots, in the same fashion, forever. Companies don’t like the treadmill problem because it’s a waste of time and resources that could be spent elsewhere, and ultimately, since bots will most definitely just move elsewhere, having someone sit around and just ban bots is not a long-term solution.
There’s one more thing to note before moving from the “bots in BGs” discussion. These bots are most definitely getting the gold to sell by farming honor, buying gems, and then selling them. However, this is probably better than chasing them off into the open-world or instance farming. In the case of honor farming, they don’t actually generate gold, only gems, and then they’re moving around other people’s gold instead of gold they farmed. It doesn’t actually cause inflation because they aren’t increasing the gold in circulation. The effects are less severe than if the bots were forced to farm old instances for raw gold or something.