The enterprise use-cases have to manage immensely more complexity than F(L)OSS projects, but at the same time, they want the agility and features of those lightweight services. (Without forgetting to CYA: document and hide as much information as possible.)

But in a sense a ticketing system is a double-ended marketplace of work: supply (fixer, be it IT, marketing, sales, admin) and demand (customers, be it internal or external).