It is a complicated system.
There is a great demand for adena and drops:
So, companies employ bots in order to supply adena to players who are willing to buy it for real $
Players also employ bots, in order to get adena and drops
Bots make life difficult for players, specially in quest locations or territories with high demand
On the other side, with current adena & drop rates, bots help to the reduction of prices. Some weapons, armors or mats would be much more expensive if there were no bot to farm them in great quantities.
So there is a trade off....