I think that there's a distinction to be made between copying code and copying design.
Design is hard, and even though a design might be quick to implement in code, that doesn't mean the design was easy.
Just look at the Samwer brothers - they clone every good startup that comes out. Is what they do okay? Maybe they don't copy any of the code from the successful site, but they shamelessly copy the design, which is often the hardest part of the creation process and the main reason why the original site was so successful in the first place.
Didn't see this and brought up the Samwers as well. I think we're still in a transition around here in terms of how "design" is valued but overall it seems like things are improving.
Design is hard, and even though a design might be quick to implement in code, that doesn't mean the design was easy.
Just look at the Samwer brothers - they clone every good startup that comes out. Is what they do okay? Maybe they don't copy any of the code from the successful site, but they shamelessly copy the design, which is often the hardest part of the creation process and the main reason why the original site was so successful in the first place.