Unification was reasonable at the time, given the goal to fit Unicode in 16 bits, and willingness to exclude obsolete characters. It's just that they followed o

Unification was reasonable at the time, given the goal to fit Unicode in 16 bits, and willingness to exclude obsolete characters. It's just that they followed official Japanese standards, and therefore unified too many from the point of view of other languages. I think the first big mistake was using postfix/infix operators (combining characters, modifiers, variant selectors, joiners, etc.) rather than prefix, preferably in blocks by arity. That would have simplified processing (in particular a keyboard dead key could have been identical to a combining character) and made broken sequences detectable. The latest big mistake, I think, was retroactively changing some non-emoji characters to have “emoji presentation”, which means that some text has to be edited to preserve its original appearance.