I'm a longarm quilter and lucky enough to be very busy.
I get to see lots and lots of quiltmakers' quilts up close and personal. Quite often when someone bring their quilts to me, they start the conversation by pointing out the flaws in their work. I always stop them and tell them the quilt police don't live here, and if the quilt police knocked at the door, I will NOT let them in!
There are some basics that we want in our quilts. And from a longarmer's standpoint, these make for a really good quilt. A quilt should be flat. The seams should be sewn, not open. The top and backing should be well pressed. Stray threads should be cut off. That's about it for the "should" list.