One of the reasons was the fabrics I had chosen. The class required we buy our fabric ahead of time, so I went to the local chain store and bought away - mostly poly/cottons of course, because that was the biggest selection. I think the instructer did us a big disservice not to use the first class to teach us about fabric quality, type and even how to make colour choices. Especially since it was a beginner's class. As a broke student, I couldn't afford to replace the fabrics I purchased with cottons, so I made my sampler quilt blocks with my original purchase, and was never happy with it, so into the UFO pile they have sat for 30 years. I did finish the pillow with hand-quilting, and it still hangs around with it's lumpy batting fill and all.
Now that I am back into quilting, I was trying to explain to my friend K why it's not always the best choice to go to the chain stores to purchase fabric for your special quilts. Here is an article I found that explains it best:
Quilt Fabric Shopper's Guide to Fabric Quality
This came from Suite101 posted Dec 27, 2007 by Christine Mann