Why is recognizing someone else's work so much pain?
The whole point is that copilot forgets who wrote the code and who is the author of the whole idea (unfortunately few programmers write it but sometimes it is there is you are patient enough to read documentation). Thus a copilot's user cannot know who deserves the credit.
This whole discussion is like if you train an AI to pick apples from a supermarket and leave them on the street waiting for someone else to take them home, and pretending that nobody is stealing anything.