Because it's easier to throw in random icons than to actually accomplish the goal of "every letter in every language in common use for the past 200 years", or even "past 20 years".
Or, put another way:
'We have an unambiguous, cross-platform way to represent “PILE OF POO” (), while we’re still debating which of the 1.2 billion native Chinese speakers deserve to spell their own names correctly.'
This is a link by the article's author that is intended to make it easier for us to add useful symbols: https://github.com/jloughry/Unicode
I recommend you use it to add any glyphs that you feel are being neglected.
That article raises an interesting issue about a character in the author's name that is missing from Unicode. Unfortunately the article is (how to put this?) not constructive. The complex reasons that Unicode excluded the character are described in [1]. If the author addresses those issues, there's a much better chance to get the desired character into Unicode.
Correct me if I'm wrong, but isn't the Han Unification project more about unifying semantically distinct, but visually identical characters under the same codepoint (rather than grouping together similar-looking codepoints as the article suggests)? As far as I'm aware it's more along the lines of reusing the codepoint for 'a' when encoding both English and Spanish text. Am I mistaken in thinking this?
Or, put another way:
'We have an unambiguous, cross-platform way to represent “PILE OF POO” (), while we’re still debating which of the 1.2 billion native Chinese speakers deserve to spell their own names correctly.'
https://modelviewculture.com/pieces/i-can-text-you-a-pile-of...