Or maybe they are not bots, instead players just playing AH.
I'm playing AH relatively frequent. Can not relate to this "omg bot king sits on top of AH" narrative.
What is actually happening is you have no notion about scale of things, that's why everyone is Bot to you. Lots of people have millions worth of reagents, BoE's, you name it stashed because they can't keep it in gold(squish). then they one day decide to get something for coins, for a new alt, etc, they sell some of their stuff and sell that gold on site. Don't underestimate what people are capable of just because you can't see anything like that in your wildest dreams.
Sure there are bots, people who frequently post inhuman amounts of herbs or ores seem to disappear pretty fast tough.
P.S.
Your "3 stacks per hour" thing - you can shove it, it's absurd. I'm not a bot and I have even up to 3000 active auctions.