Kenneth, You are ABSOLUTELY CORRECT! How great of you to actually look at Bret's listing. https://www.airbnb.com/rooms/24848659
It sure does look like he is offering accommodations to the general public - just outside of a Texas state park. But, they do things differently in Texas, yeah? 🐵
And there are photographs & logo of his General Store in the listing, so of course, people know they can call directly ... circumventing Airbnb's policy of trying to keep people from negotiating off-site.
So, my opinion is that Bret does not have a complaining leg to stand on ... ... ... BUT the "issue" is quite a relevant one. Guests RARELY read the listing details and FREQUENTLY ignore the house rules and do not pay for extra people. As an Owner, the trick is figuring out who those people are before allowing them to stay in your house. I'm trying to develop that Spidey-sense!