I doubt very much there is any place in the US where overnight occupancy is 0 for a commercial property. Where I live you can have a 24 hour business. Living in commercial property is forbidden, but what exactly is living is up to the code officer. In my case the officer decided that homeless did not live there but just visited the business.
Ok by why does the code officer enforce the zoning code in residential zones but not the commercial ones? It’s not like anyone doing their job in good faith could confuse a business patron and someone camping out in a parking lot.
Seems like your code officer is obviously crooked. Not sure what that has to do with zoning though.
Camping in front of business is not against the code, people used to do that for big movie openings or for other commercial events some time ago. With the residential property there are actual overnight occupancy limits which are easy to show being violated. And the occupancy is just one of the codes which would be easy to prove violated by a camp on a residential property, there are tons of other codes. Where I live, you cannot replace an exterior door without a permit, while the commercial zoning is much more permissive.