I don't know that I would dislike a quilt so much that I would not use it. I appreciate all the time and effort that goes into each item and can admire the beauty in that.
What that being said, if I truely did not think I could use the quilt, I would still sincerely thank the maker for the thought and effort. I would then tell the maker that I would love for the quilt to go to an individual that will provide it a "home" it truely deserves and ask if they would be okay with me providing it to a charity to be auctioned off as a fundraiser or if they would like to returned to them and for them to find it the proper "home".
But I think I can find a "home" for all kinds of quilts with me!