Apple spearheaded this but you could imagine Facebook spearheading it and everybody else following.

Honestly the original gun emoji was simply a bad idea because it makes it hard to make apps that are age-rated for small children when there's a fricking gun in the system keyboard.

I don't understand how "there's a fricking gun in the system keyboard" => "hard to make apps that are age-rated for small children". It's just a tiny picture of a gun, hidden in a pile of hundreds of emojis at that. Where's the problem?

There’s also the knife, bomb, cigarette, and middle finger emojis. And Apple decided to keep the peach emoji looking like a butt:

https://techcrunch.com/2016/11/15/apple-brings-back-the-peac...

It was quite literally leftist virtue signalling. A way for those companies to say "I support gun control".

I support gun control but do not support the censorship in emojis. So I don't know about that.

If you're making such an app, you'd be filtering the content for obscenities anyway. I mean, Unicode already includes a swastika character [1]. Wouldn't you just add the gun emoji to your list of censored words and emojis?

[1] https://en.wikipedia.org/wiki/Swastika#Written_characters

Per your link, the swastika is a religious symbol for a large number of people for a long time. It's strange to suggest that it is an obscenity just because a small number of people used it to mean something bad.

Why?

I’m a youth firearms instructor - are you saying that any app that contains so much as an icon shaped like a gun is inappropriate for children?

Having a character in the system font does not mean having it on the system keyboard.

Unicode doesn't decide anything about character appearance. Unicode is just about giving a character a number (among other interesting things for text, like collation, bidirectional text, etc.).

If Unicode issue a standard naming U+1F49A as 'Green Heart' and all major platforms implement a green heart, I'd say unicode decided something about character appearance :)