Sometimes gamblers gamble just for fun. In such situation they don`t need a bot, they need to enjoy the all moments of the game. But when someone gamble for profit - he don`t need to make one sequence of actions time by time. To automate this process and don`t spend time they use gambling bots.
It is true. Gamblers who only play gambling for fun will not use bots because it will reduce the fun moments they can get. Also, if they don't use bots, they can switch from one gambling game to another to have lots of fun. The use of bots is only to automate the gambling process carried out by gamblers so that they can do other jobs. Or maybe they have some other purpose in using the bot that we don't know. So each gambler will choose whether to use bots or play manually.
One more purpose is not to count. If the strategy looks like some type of martingale, or may be some other but that need to count too - the bot doesn`t mistakes and players can.
I can`t say correctly for what purposes the bots used but i think that there are 2 main ideas: to automate process of gambling and to avoid mistakes.