Writing in a language the reader doesn't understand is ... not so fine.
Writing in a way to give the appearance of one message but the machine-recognised existence of another is ... wrong, malicious, and harmful.
At root the issue is that encodings and graphical presentations aren't the same thing. 7-bit ASCII is limited and constrained, but as a universally understood encoding those specific characteristics are useful benefits. Yes, it means that representations are limited. But that's the essential trade-off for a lack of ambiguity.
And even within ASCII, there are homoglyphs or near-homoglyphs: {0O,1lI, 5S} being the most frequently encountered. Kerning and ligatures may present others, as with {m, rn}. In historical documents, distinguishing {ſ, f}.
Let me rewrite that from the opposite perspective.
The reason I use it is so that I can write in my language.