What I have discovered over the years aside from the lousy patterns you have all been talking about is that many people, even instructors of quilting don't have a basic knowledge of sewing dos and don'ts. Things like straight of grain etc. are very important in the successful creation of anything made with cloth. Those who have some training in garment construction are able to create quilt related items with a much better outcome. Knowing when to stabilize a fabric and what to use for a stabilizer etc. can mean the difference between success and failure especially when making accessories or things that will hang. Using fabrics of similar weight and density of weave produces I much more pleasing finished work. We have all seen beautifuly pieced items that were marred by seam allowances showing through because the lighter pieces were to transparent for the darker ajourning pieces etc. A basic knowledge of different stitch lengths and their uses also produces a better outcome. Quilted garments or accessories that fall apart when laundered probably were not properly stitched or the fabrics were not compatable.
New quilters will be more successful if they get some basic instruction in sewing skills before investing in expensive materials and lots of gadgets for quilting.