typical grape juice has 50% more sugar than Coca-Cola. http://en.wikipedia.org/wiki/Juice
Orange juice 170 calories from sugar vs 150 for cola (12 oz) http://www.hsph.harvard.edu/nutritionsource/how-sweet-is-it/
Googling "sugar in apple juice" turns up 170 for 12 oz as well.
This is entirely psychological, right? What about soda would make it more refreshing physically than water?
In New York I've never had any problem finding seltzer. My parents buy it every time they go to the supermarket in upstate New York.
I'm trying to think of how common it is in corner stores. I can't say I've ever looked particularly hard for it. I used to keep my refrigerator in Buffalo stocked with the stuff though. It sure is refreshing.
Thankfully my work provides free cans of seltzer which I drink like water (heh heh!). Although I occasionally wish they would get the kind with a citrus fruit flavoring instead of just plain.
When my parents took us on holiday to America my little brother refused to drink either plain water or fizzy drinks, but we found orange squash in the British section of a large supermarket.
As Wikipedia says, it's the default drink for British children. Adults who drink it probably pick a nicer product; my manager keeps a bottle of elderflower cordial in the cupboard.
I don't like making generalisations about Europe, but carbonated water is sold in every shop in Europe that sells bottled water. In some countries (e.g. Georgia), in smaller shops, you will only find carbonated water. In Germany it's what you get if you order "mineral water", you have to specify "still mineral water".
And restaurants in Europe can't seem to give you just plain water unless you specify. I spent my entire vacation being surprised by bubbles before getting what I wanted.
I don't remember the last meal I ate with adults where people ordered soda. It may be that every once in a while I'll be around a recovering alcoholic who orders a soda, but usually it seems they order something like sparkling water.
It's probably a regional/class thing, since I live in NYC. Maybe in the middle of the country or in a working class household you'd be more likely to see people drinking soft drinks with a meal?
1) Sugar is addicting, and there is significantly more sugar in soda than other drinks [Google it]
2) Soda is very refreshing. This is important in warmer climates. If it is 98 degrees outside (37C), an orange Fanta does a much better job of making me feel better than just water
3) Soda is available everywhere and is the de-facto drink with most meals. Just like Italians drink wine with dinner, Americans have soda. This is perhaps the most important factor: If everyone is drinking soda, why wouldn't you?