I have always wondered why these guys put more bots in the game indeed. As far as old forum member NIK mentioned they did it once.

Put the bots and let the guys play, guys. It’s a win to win after all.

You have already earned a lot from these guys and you target are the newbies and the veterans know the game, meaning they won’t invest much at all.

But I am guessing they might do it for the increment the amount of alter account creations.