> The native alphabet for most Southern Slavs would be Glagolitic
That's a bit of an exaggeration, the Glagolitic script was only ever used by scholars, the earliest Cyrillic writings are not not even 50 years older than the Glagolitic.
You're right that the Cyrillic is indeed way closer to the Greek alphabet than the Glagolitic, despite being named after Cyril. I'm not complaining about the "forsaking of culture", I just found it interesting that I was being "mono-cultural" for disagreeing with the existence of a few weird Unicode code-points that themselves are a direct result of someone's attempt to move towards a "mono-culture".
What I'm complaining against, if anything, are overly complex standards. This is just one of what's probably 100 different quirks that you should be aware of when working with Unicode text, and this one could've been easily avoided by just not including a few useless characters.