I mean that person was wrong, there are absolutely places where mixed use setups like that are a thing. It’s rarer but it exists. Zoning laws suck and aren’t a good reason, but it’s also not a good reason because there are places that don’t have this issue. Also if it was like that when it was built and has been used like that since forever they allow it by grandfathering it in, not a forever solution but it does happen.