How to disable emojis system-wide? I never want to see an emoji again.
I have seen instructions for disabling them in specific apps, but I want a nuclear option.

How do I get rid of them for all apps, all users, all contexts?

I'm on OSX 10.10 Yosemite
You might be able to remove Apple's Color Emoji font, but you cannot remove it with FontBook. Instead, go to /System/Library/Fonts/ and drag "Apple Color Emoji.ttf" to the Trash. You must authenticate yourself as an administrator to do this. I haven't tested this, and I don't know if your computer will catch fire.