Your expectation is common among westerners. It typically goes away within a few days of beginning to work with large amounts of CJK content. When someone says

Your expectation is common among westerners. It typically goes away within a few days of beginning to work with large amounts of CJK content. When someone says they accept UTF-8, UCS-2, or any other encoding, my first question is always "Are characters outside the Basic Multilingual Plane supported?". There is a long history quite apart from MySQL of the answer to that question being "no", particularly if the project in question originated in the 90s (or even early 2000s).