You're referring to something like?

    objA.funcA().funcB().funcC()

I believe the issue is that it cannot easily be extended with new functionality since all of the methods must be members, whereas operator| can be defined as a free function which allows one to write new chainable functions without altering the base library.

I agree that a function chaining syntax would be preferable. LINQ to Objects in .NET can do something like this because the language(s) support extension methods.