I'm not disputing its origins a hundred years ago as soda water. Just saying that it is irrelevant. If I say I am saying soda short for soda pop, then that is what it is short for, and I'd bet that would be the case for most people nowadays.
See my last paragraph. For you, it is short for "soda pop". For me, it is not; because the word "soda pop" is not used around here, nor has it ever been. While your ancestors were coining the term "soda pop", my ancestors were saying "Soda pop? That sounds silly. I'm not calling it that."
I completely disagree about the best tasting soda btw. I'd take a bottled over a fountain soda any day. Fountain soda is far too inconsistent and usually not at a mix to my liking.
Get it from Burger King, one which has their soda fountains in order (it should come out of the nozzle smooth, not splattery). McDonald's is usually good too, but not as good as Burger King. And yes, it can be inconsistent, but when its good, it is as good as it gets IMO. However, the worst Coca-Cola I've ever had was also from a soda fountain; one of the little coin-operated ones in a few factories I used to work at (all serviced by the same company). That stuff was even worse than Coca-Cola from a plastic bottle (which I generally consider to be the worst form of Coca-Cola).
My ranking is as follows:
1. Fountain Coke from Burger King
2. Fountain Coke from McDonald's
3. Mexican Coke from a glass bottle (made with sugar)
4. American Coke from a glass bottle (made with HFCS)
5. Coke in an aluminum can
6. Coke in a plastic bottle
7. Coin-op fountain Coke from various places
I most often drink Coke in a can, because my top 4 choices are not available at the grocery store.