Please keep in mind that automatic trading doesn't mean the bot will decide every trade. As a trader it only helps making trade faster and easier with the set of guidelines provided by the trader. It does increase the chance of earning profits but the decision to invest and exit has to be taken by the trader operating the bot. It is not an AI that takes all decisions in account to make a successful and profitable trade.
You’re correct that bots needs to be setup first base on user preferences before it will do automatic trading but the existence of copy trading makes the job of automated trading with the decision of others is possible.
Copy is now very popular instead of bots since exchange shows the winning percentage of each copy traders that helps user to decide who to follow for copy trading. This is much better than bots if you have poor trading skills since it’s like hiring fund manager to trade your assets but the only difference is just you are copying his personal trades.