[hkuo]

The issue of being "inspired" by other people's designs does not appear to be a relevant case here. When the degree of stealing is a practical copy and paste, it is more in the territory of stealing than inspiration. It might be better understood if you think of it as music. I don't know what they are, but I believe there are legally specific percentages of how much a melody or chain of notes needs to be changed before it is not considered the same song.