100% agree. I'd like to be able to tell mobile Safari to just ignore that setting. Maybe there's a way and I missed it. Wouldn't be surprised, these old eyeballs aren't what they used to be and that exactly why I want zoom to always work. Some of us actually need it.
Heck, back when I bought my mother her first iPad, this was the whole reason. She was getting eye surgery and wouldn't be able to see well, and would be stuck face-down for a couple weeks. I figured an iPad would be good, because she could pinch-zoom so the letters were two inches tall if necessary. It was a roaring success, but zoom=false defeats that.