At my house we have spent quite a bit of time discussing this topic lately, mainly because my boyfriend is still trying to understand what all the hubbub is about ;) He has a background in graphic design, however, so he understands the broad strokes of the controversy as it is the same debate that has been going on in the world of art and design for ages.
There is a ton of content out there for you to wade through, and I encourage you to do a bit of reading and come to your own conclusions... but in the meantime, here are a couple of interesting videos on the subject:
Creativity is a Remix by Kirby Ferguson
All Creative Work is Derivative by Question Copyright
Edited to add: I was just watching the Definition: Modern Quilt webinar by Mary Fons and if you haven't watched it, I recommend it. She spends some time talking about the 'roots' of modern quilting in the Amish and Gee's Bend quilts and shows some great examples of both modern and antique quilts side by side where there is a striking similarity... I wonder if the modern quilters asked permission and gave credit? ;) I think this slide sums it up nicely: