Why is the Sarcosan Wave Generator considered heretical tech?

According to the wiki, if installed in a body before death, then the resulting reanimated corpse is mentally the same as they were before death. The main differences being that the body is still dead and the persons soul doesn't come back with them. The Imperium already allows people with the Pariah gene to exist, the emperor himself is well known to be suffering from necrosis, Servo Skulls are common, and some people even have servoskulls attached to their bodies. So what is there to complain about? That's not even to mention the fact that synskin, and cybernectics exist so it wouldn't be hard to replace and cover up any rotting tissue. It's also been confirmed that formaldehyde isn't lost technology in the 42nd millenium.