As of now, the main issue is that people don't see up to the fact there can be censorship options, parental controls of a sort. All they see is that there's blood and children are going to see it. But even if there are censorship options, they can only be activated if the player wishes them to be, because they're - as the word suggests - only optional.
It would be nice to have a version of Diablo for kids to play without having to worry about their necromancer blowing up corpses. However, the media would only see there's blood in the game and that's all they would need to demand removing blood from the game entirely. Children can still blow up corpses if they wanted to. Switch the option over, it'd be right there in the pause menu or wherever else, then Diablo's back to how it was originally.
There could be parental controls, this is the most we could do to have optional censorship, but would it not be pedantic to enforce? Consoles have parental systems, but individual games? They'll be played through once and forgotten about most of the time. It's pedantic to enforce so unless there's a way, I think it's better to forget about this idea.
Ultimately, perhaps it would be okay to have kid-friendly versions of M rated games, but it's not a priority for me. Give me all the blood and gore first and foremost. It's an M rated game, don't go through all these hoops simply so the game is accessible for little Timmy as well, don't waste time if it's time that's going to be wasted. They'll still complain it's only optional even if censorship features were introduced.