Most quilt patterns are in the public domain. The old ones. Most designer will say that you can make the item for fun and profit but not mass produce, which means, to set up a factory.....
Why would I purchase a book or pattern if I can't sell what I make if I choose to do so. When I make a quilt I am under no obligation to say who designed the pattern. I have payed for it and the work is mine. If I want to share the designer's name so other's can make the quilt, I will gladly do so but it will not be on my label.
The same applies when I paint ornaments or some cute stuff out of one of my painting books. I sign that piece with my name. I painted it. There is no need to say who designed it.