At work I come across a lot of Japanese text files in Shift-JIS and other encodings. It causes many mojibake (unreadable character) problems for all computer users. Unicode was intended to solve this sort of problem by defining a single character set for all languages, and the UTF-8 serialization is recommended for use on the Internet. So why doesn't everybody switch from Japanese-specific encodings to UTF-8? What issues with or disadvantages of UTF-8 are holding people back?
EDIT: The W3C lists some known problems with Unicode, could this be a reason too?
Best Answer
In one word: legacy.
Shift-JIS and other encodings were used before Unicode became available/popular, since it was the only way to encode Japanese at all. Companies have invested in infrastructure that only supported Shift-JIS. Even if that infrastructure now supports Unicode, they are still stuck with Shift-JIS for various reasons ranging from it-works-so-don't-touch-it over encoding-what? to migrating-all-existing-documents-is-too-costly.
There are many western companies that are still using ASCII or latin-1 for the same reasons, only nobody notices since it's never causing a problem.