Simply put, it's called the "Step On A Crack" apologetic - it's considered blasphemy to do anything that might depict the Virgin Mary(TM) in a less-than-Catholic way (including suggesting that Mary suffered labor pains in giving birth to Jesus).
The Virgin Mary(TM) is a registered trademark of the Catholic Church. All rights reserved.
The other stuff though, like the hyper-inflation of the remainder of the tenets of "Immaculate" they do hold ownership of. I won't argue that. It took a few centuries to become fully fleshed out.