It is the intent of the bot writer that may be good or bad, not the bot.
The network should be bot-friendly, and people should be free to use them or not as they see fit for their purposes.
The exchanges are evolving to meet market conditions, and while some bots may be a nuisance now, or even outright detrimental, in the long run they will only help strengthen the network.
A major problem with exchanges is lack of liquidity. This lack of liquidity is a source of volatility. Add liquidity and you reduce volatility. Bots (and other forms of high-frequency trading) add liquidity and reduce volatility.
