I don't see why this would be a question at all. Firstly, I never stated that this survey is about external file browsers as you should see because of the other questions and secondly it shouldn't matter because this is simply a survey about the way you use file browsers and not an attempt to convince you to use some alternative product. This might as well be some sort of psychological research. I am not saying that it is, but it could be a possibility.

Also there are scenarios where the file browser that comes with the operating system cannot be used. For instance, if you want to access files in your company's network from a remote location and the company doesn't allow you to use a remote desktop protocol to access them.