was this a total surprise for your inlaws, or did you discuss it with them first? I would never give a KS quilt as a gift unless I know the person wanted it and had picked out colors and patterns. That is a BIG gift - like giving someone a sofa!!
Not everyone is a "quilt person" - some people would rather have a bedspread or duvet on their bed. That being said, they should have expressed more appreciation for your gift or ANY gift.
Depending on how well you know them, you might ask if they really want the quilt and offer to make or get something else for them instead. Then give it to someone who will like it.