I always thing of the Amish, deliberately putting a mistake in the quilt because "Only God makes perfect." I laugh, because I NEVER have to add a mistake- there are always plenty already there.
For me, if it can be used and loved, and it was made the best that I can make it, it's fine. Quilts are love, and they shouldn't be stuck in a closet because the quilter doesn't think they are good enough. trust me, someone else will love it to death and appreciate it.