It's more than just semantics. 21 million Bitcoin and 2.1 quadrillion sats.
Renaming sats to Bitcoin means theres now 2.1 quadrillion Bitcoin. Yes the value stays the same and its just simple semantics for existing Bitcoiners. But for the precoiner, this adds yet another barrier to understanding Bitcoin.
In a vacuum yes it makes things easier to understand. But those of us living in the real world actively orange pilling have to acknowledge 17 years of literature and education stating 21 million Bitcoin. Try explaining to an impatient low attention span fiat NPC why Bitcoin is suddenly 100 million times less valuable and Bitcoin =/= Bitcoin.
If you have to rename it, calling it literally anything but Bitcoin would be less confusing.