To be fair, mozilla uses bugzilla to track everything, not just "bug" bugs. Each new feature in development has a bug, or multiple bugs. When code is refactored there is a bug for that, when somebody wants commit access there is a bug for that, when an employee needs a new laptop there is a bug for that, when a community organizer wants some money or gear for an event there is a bug for that, and so on... Other organizations use their bug/issue trackers in a similar manner.