My quilts aren't warm either - nor do i expect them to be. Granted, I only use cotton batting. But, if i want really warm, then it's going to be layers - and hauling out my wool blanket from years gone by. My one "quilt" that is the warmest is warm because the back of it is flannel. The top - which is scrappy w/ pieces of wool, corduroy, and flannel only has an old flannel sheet in between the layers.
For me, warmth is added w/ fuzzy type materials, not smooth cottons.