Gentlemen, thank you for your objective discussion.
There is a time and a place to use a solid, but the patented pressed plunger with its hidden air-pockets, is the real secret behind Peregrine's flat meplat VRG-3 BushMaster and the spitzer VRG-4 PlainsMaster hunting bullets. Instead of scoring (pre-weakening) the bullet to produce petals, Peregrine's hunting bullets open up into a complete mushroom of 2-3 calibers. An 8mm bullet becomes a 20mm hole punch. Petals have the disadvantage of breaking off when one of them hits bone, which can cause the bullet to change direction. In addition the flatnose BushMaster acts like a hole punch when it penetrates the skin of an animal. This "apple corer" concept is also incorporated in the Toxic Broadhead. A punched hole in the skin doesn't close back up as when shot with a spitzer, which leads to devastating blood loss and easier tracking.
Ever since Robert Ruark (Author of "Use Enough Gun"), ethical hunting has been about killing the game animal as quickly as possible, while minimizing meat damage. An exploding lead-core bullet will kill the animal, but it will also destroy edible meat, leading to "unethical" waste and possibly lead-poisoning. This green thing isn't just about lead in the environment; it is also about lead in your body. If the bullet itself can do more of the killing because of superior design, there is less need for a massive bullet, associated recoil, flinching problems, missed shots, bad bullet placement, etc.