It's not exactly for no reason. You just have to examine the politics behind it.
The Chinese gov. is avowedly atheist, as is a common feature in communist governments, as communists tend to believe that religion often serves to keep the masses pacified, and thus unaware that they are being short-shifted on the whole wealth thing. So when it comes to censorship, they block anything that relates to pre-communist Chinese beliefs, which focused around the ancestors. No one can deny that skeletons are remains of people who once lived, so they could easily be considered a symbol ancestors. In a Chinese context, one could potentially read a game prominently featuring animated skeletons having influence in the real world as propagating this belief (or as the Chinese gov. likes to call it "superstition") in the ancestors. Thus the denial, as such a game would have a pro-religion (and thus anti-government) stance, however accidental.