The reason they can be handy is for when trying to (for example) make named constructors in a class library (for example, my simple one called
lowclass. In ES6 classes, class constructors are always named functions, and their name is that of the class.
Briefly, lowclass aims to allow a developer to strategically use different types of classes (they have different performance implications), not just ES6 classes. In lowclass, which currently only produces ES5 constructor-pattern-style classes, emulates ES6 named constructors. It'd be nice to have an actual API to make that happen with, and then assigns the constructor to
Class.prototype.constructor of the created class, which is another behavior of ES6 classes.
I think that dynamic naming of functions similar to ES6 property initializers would be great, like in my previous example.