Yes if the bot won each time, users won't be encouraged to play as much. My assumption is that if a user's challenge activity reduces in terms of closing weapons for over a week or more, as soon as the weapon is reopened, the bot has a high probability of challenging the user to encourage him/her to keep going.
Yeah! Abieyuwa Idehen SoloLearn tend to let you win challenges so you get the encouragement to take more challenges, BTW, taking challenges is a good practice of learning ! That's why the bot was programmed like, just to encourage you to learn from challenges.