The reward is inherent to the activity: independantly of the intrisic quality of one's work, programming is interesting. In the Philosophy of logical atomism Russel suggests that if your life is boring or unhappy you should try to start practicing logics or mathematics and experience a relief. Programming is the intellectually poorer's way of applying such a precept. Then - if you want to maintain this state of mind safe from damaging criticism - you can keep your work for yourself; it'll do too and remain an unknown pity for the ones who'd have found value in your contribution.
Update: It would have been better to speak of "logic and mathematic" instead of "logics or mathematics" in the context of Russel, and this is perhaps not unrelated to the kind of reward he was thinking of.