He asked why not in reference to your original statement, or at least thats how I read it.
I was only giving my opinion in a reply to yours based on my own experience in cold water with bouyant fins and not needing anything additional to combat or offset air in the legs or ankles. For me it was just getting use to the fins and bubble management. I personally was glad I gave time instead of adding additional items to my setup.
Though I also agree there are many reasons why someone might prefer a less buoyant set.
I do look forward to trying these out in some cold water. Though warm water too if I can get extra full pockets easily before my December trip.