I'll say it again: this is the consequence of Unicode trying to be a mix of html and docx, instead of a charset. It went too far for an average Joe DevGuy to understand how to deal with it, so he just selects a subset he can handle and bans everything else. HN does that too - special symbols simply get removed. Unicode screwed itself up completely. We wanted a common charset for things like latin, extlatin, cjk, cyri…
we didn't even get that because slightly different looking characters from japanese and chinese (and other languages) got merged to be the same character in unicode due to having the same origin, meaning you have to use a font based on the language context for it to display correctly.