I don’t know if anyone can phrase it better than the Judges themselves: http://scavhunt.uchicago.edu/lore.html
The goodness or badness of Scav is a philosophical question and a matter of some debate. One grad student who went to Harvard was rather famously [not a fan](SCAV bothers me. I'm fine with nerds having fun in an overindulgent nerdfest. Wh - ■■■■■■■■■■■■), but most people like it.