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, cyrillic, hebrew, etc. And we got it, for a while. Shortly after it focused on becoming a complex file format with colorful icons and invisible symbols, which is not manageable without cutting out all that bs by force.