Perhaps some more information should be provided on the web site or in campground literature, to the effect that some or all sites are not tent friendly. And if it is designated as a tent site, it needs to be tent friendly.
I would be annoyed and setting up on the grass too, if I paid for a tent site, and arrived to find no good spot for a tent.
A cursory review of the site on the reservation system will show a picture AND lists the driveway surface BEFORE you even make a reservation, never mind driving there. I don't know what else you would need.
The common rules are listed on the back of the map supplied at check in. Please read them.
The tent issue is only an example of the decline of campers activities. Loud Music, excessive alcohol use, improper parking are others.
It just seems to be a lot more issues this year. Have other work campers experienced this?