To add to that, it would be quite a headache if source was found to have been copied from elsewhere (e.g., a developer copy & pasted code). Even if it was merel

To add to that, it would be quite a headache if source was found to have been copied from elsewhere (e.g., a developer copy & pasted code). Even if it was merely "similar looking code" independently developed, the risk of a lawsuit seems like it would not be worth it, especially given that there's not really much/any direct benefit for the publisher by publishing the code.