Why are constructors not inherited in C#?

If you think about what would happen if constructors were inherited, you should start to see the problem.

As nearly every type in .NET inherits from Object (which has a parameterless constructor), that means almost every type that you create would be forced to have a parameterless constructor. But there are many types where a parameterless constructor doesn't make sense.

There would also be a problem with versioning. If a new version of your base type appears with a new constructor, you would automatically get a new constructor in your derived type. This would be a bad thing, and a specific instance of the fragile base class problem.

There's also a more philosophical argument. Inheritance is about type responsibilities (this is what I do). Constructors are about type collaboration (this is what I need). So inheriting constructors would be mixing type responsibility with type collaboration, whereas those two concepts should really remain separate.

Sometimes, when subclassing, you want to restrict the conditions required to create an instance of the class.

Let me give you an example. If classes did inherit their superclass constructors, all classes would have the parameterless constructor from Object. Obviously that's not correct.