I'll throw in my 2c worth of noticing here. I recently spawned a monk bot because I had some extra mnk/bst weapons lying around and wanted to test their dps. Now, i'm far from a hate generating machine as a bst unless I REALLY want to be, but even a naked and weaponless monk bot would steal aggro in under 5 seconds every time it attacked. (Literally, timed it.) At first, I thought it was a bugged bot and remade it, but came out with similar results with the new bot. As it is right now i've been feeding her my castoff gear in hopes of making a tanky melee dps in the future, but the bot is unusable in it's current incarnation.
From the dps tests, and using the bot for a bit, I highly suspect an issue like a previous poster suggested is happening in that the monk skills are drawing more aggro than the damage they apply. This is the only thing that would make sense as the weapons, or lack thereof, don't seem to change the amount of aggro the bot produces. I have no problems with the rogue bot or ranger bots, on the other hand, unless i'm not paying the mob their attacking attention.
Go figure.
