Hot take: Why do people think it's okay to have a feast on brand new carpet?

Just finished a full day putting in plush carpet for a nice family. They decided to order a giant pizza right after I left. Came back the next day for a trim check and saw grease spots all over. Now I have to argue about who pays for a cleanup or patch. Do people not get that carpets need time to set? It feels like they see new floors as an instant party zone. Makes me want to put up warning signs or something.