Once you work hard in order to find a way to make profits out of the markets it is going to be very difficult to share it with anyone even if you charge money for it, the OP took 3 years in order to create this bot, so selling it is probably not a good idea right now even if it is really profitable, probably the best option for the OP is to profit from his bot and to keep improving it for years or even a decade and only once he has enough capital to create a business around the bot he may try to do so.
You are right because he will like to secure the information for personal use only, or before the information is been dispense or circulates maybe their will be an option of selling the methods of making profit if it happens to work properly, this is from my own perspective
And I personally think this is the right approach, people fail to realize how difficult it is to actually create a strategy that can make money out of the markets, and to create a bot that can execute that strategy is way more difficult, so after so much effort has been put into such project it is very difficult for the developer to actually release it without trying to profit from it in order to recover all the time, energy and money that he has spent trying to create such an exceptional bot.