True, but times are hard and not everyone (myself included) has money to run to the store and drop a few hundred into their system...
Which is why CPU physics doesn't make any sense. Lets see, buy a ~$200 quad core for a mediocre physics improvement that is still stuck on rigid bodies, or a $50 GPU for a radical leap in physics that brings cloth, fluids, and deformable objects. Yup, real tough choice there.