Of course this is a matter of personal choice and every quilter can decide how much quilting he or she wants on a quilt. IMHO there are two different techniques competing against each other on a pieced quilt and it is a challenge for the quilter to find the right balance between those two. They should harmonize.
On a wholecloth it's a completely different thing: you only work with on single technique on a consistant surface and the structures and patterns created by the quilting don't have to fight against something else. I have never seen a wholecloth that was overdone, especially when the quilt was hand quilted.