I get where you're coming from, but many of the social etiquettes come from a very class-based world and society. Do we want to further encourage that? Also, the fact that someone worked hard doesn't mean a certain outfit should be expected. I work hard as a programmer and nobody puts on heels, a nice dress and suit to see me do a demo of the app I built. As long as what people wear is clean and doesn't smell, it's fine. I do agree though that food and drinks should be kept out of the auditorium (unless required for health reasons). Slurping and munching noises are not what I paid for.