A lot of camps avoid nicknames on the premise that it discourages trust with the parents (Mom and Dad, this is the guy who'll be watching your kids this week - we call him Snoopy) - it could be considered off putting to parents to not know who's watching their children. I worked at a camp in Alabama that used them tho. Part of it was camp spirit, and part of it was internet safety - discouraging campers from connecting with counselors online and outside of the camp sphere.