|The divine comedy|
Progressive creation is a form of old earth creationism proposed as an attempt to find a middle ground between scientific fact and Biblical creationism. It holds that the world is billions of years old, and that the universe began with the Big Bang, but that the entire process was controlled by a God, who had a direct and active role in the whole affair. This is different from theistic evolution because in progressive creation the God explicitly creates many of the new forms, rather than allowing them to develop through evolution. In particular, in progressive creation, God came down and took two hominids and literally breathed a soul into them, to create Adam and Eve.
Young Earth creationists (YECs) have been treating this as a Trojan Horse of evolution and just about the worst assault on Christianity since Darwin. Most of the criticism comes from a theological rather than a scientific perspective. One interpretation of the "Fall of Man" is that it introduced spiritual death into the world, as distinct from physical death, but YECs do not make this distinction, claiming instead that there was no physical death before the Fall (which leaves them in a bit of a tricky position when it comes to creatures like venomous snakes).
Progressive creationists maintain that there was physical death prior to the Fall, which to YECs is tantamount to believing that death and suffering are not explicitly the fault of humanity, hence that the mission of Jesus to redeem the world is unnecessary. As they find this unacceptable, they condemn progressive creationism.
YECs also claim that progressive creation contradicts "science," but rarely bother to explain that part (presumably they're referring to creation "science"). Instead, they just castigate progressive creationists for wanting to fit in with the "world", using that particular fundamentalist definition of the word that means "all that is evil and wicked" and disagrees with them.