This could've been a solution but is not what Unicode chose to do (in this particular case). Also relevant: discussion around unifying glyphs like A, B, C, E and so on across Cyrillic, Latin, and Greek, all with their language-specific casing behavior.
Coincidentally, Cyrillic I/i is also a thing (and is separately encoded!):
That's correct, but this could be very surprising for anyone not familiar with Turkish. For example if you have an English text which has a Turkish word in it, maybe a place or person name. Or for example when doing OCR.