I work at a company where some require justification for the use of an Interface in our code (Visual Studio C# 3.5).
I would like to ask for an Iron Clad reasoning t
An interface declares a contract that any object implementing it will adhere to. This makes ensuring quality in code so much easier than trying to enforce written (not code) or verbal structure, the moment a class is decorated with the interface reference the requirements/contract is clear and the code won't compile till you've implemented that interface completely and type-safe.
There are many other great reasons for using Interfaces (listed here) but probably don't resonate with management quite as well as a good, old-fashioned 'quality' statement ;)