Certainly warmth isn't the only purpose for a quilt. However, if warmth is an issue, insulating properties of the batting is important. A law of physics is that trapped air conserves body heat. That is why wool is warm. Wool fibers trap a lot of air. Down also traps a lot of air. If the air is compressed out, the quilt will not provide as much warmth as a quilt with more trapped air. That is my understanding of physics. Perhaps someone else interprets this law of physics differently than I do. We make quilts to our own likes and needs and they are all beautiful and functional in their own unique way.