为什么Ninject的Mvc ninjecttpapplication不使用IControllerFactory来创建CreateControllerFactory()

I was looking over the Ninject MVC source code, and the method that generates a controller factory for overwriting the default is hardcoded to only return a NinjectControllerFactory, however as its set as virtual it would make more sense (in my eyes) to use an IControllerFactory.I was looking over the Ninject MVC source code,