Is there any reason to prefer UTF-16 over UTF-8?

Examining the attributes of UTF-16 and UTF-8, I can't find any reason to prefer UTF-16.

However, checking out Java and C#, it looks like strings and chars there default to UTF-16. I was thinking that it might be for historic reasons, or perhaps for performance reasons, but couldn't find any information.

Anyone knows why these languages chose UTF-16? And is there any valid reason for me to do that as well?

EDIT: Meanwhile I've also found this answer, which seems relevant and has some interesting links.