I am sure if you have a good formula, then it would be easy to create a good Bot that would make you some money. The problem is, no one has a great formula out there. If they did, they could just apply that in large chunks and wouldn't have to worry about getting rich anymore. I suppose they could make a bot that would sell/buy depending on the amount of money they gained which would do alright, but not the greatest.
The bots don't have the magic formula to always earn money but there were a few cases when the opposite happened.
I remember after the gox fiasco there were a lot of traders that were betting in certain moments because they predicted how the bots will react earning quite some healthy sums on this.
But then the trades were so predictable you could spot a bot buying and selling from a mile away.
The thing I wonder about is :
What would happen if all the traders would use the same bot....