The sound it makes is exactly where the name comes from. Also there were people in soda territory also calling it pop as well way back in the day. That's why the term "soda pop" exists.
You can see a D.C. newspaper from the mid 1800s calling it pop in this wiki article.
When I asked for a Dr Pepper in Tennessee the waitress said 'here's your coke'. So I said 'wait, I didn't order a coke' and she said ' it's Dr Pepper'. I thought she was flirting with me, so I started smiling at her and gave her a nice tip. This whole interaction now makes a bit more sense.
Yeah... I'm gonna need a detailed breakdown of the rationale you followed to get from "she called Dr. Pepper coke" to "she's flirting with me", if you don't mind.
And Oregon. The only people that call it 'pop' here are 80+, and it's rare for them. I used to hear it called 'pop' by the elderly all the time when I was a kid, but that demographic has been dying out for the past twenty years.
Wow, the evil forces of "coke" have made significant territory gains since the last time I saw one of these maps. I have never heard a single person call a random non-coke soda a "coke". I recently moved to a "pop" area, but I haven't received any push back from saying soda at least. I did hear some old people here specifically call it "soda pop" though.