I’m curious, what is the objection to Han unification?

Only know the discussion superficially, but from what I understood, the problem was as follows: Chinese Hanzi, Japanese Kanji and Korean Hanja scripts have the same historical roots (Han) and still look very similar when you write them — however, they are fully separate scripts with different use of letters and optical differences that are important.

However, when encoding them into Unicode, the consortium suddenly discovered the importance of being frugal with character IDs and only defined a single "Han" sequence of characters for all three scripts. You need to select a matching font to actually display the text in the script that's intended.

This makes using those characters an unnecessary hassle and also came over as a cultural faux-pas to some (essentially like encoding Greek Eta, Latin H and Cyrillic En as the same character, because they look similar and the scripts have a common history)

It also looks a bit hypocritical when Unicode otherwise goes the opposite way and has the space to encode dozens of variants of the Latin alphabet or — as we see here — several categories of dashes.