How about the sub files with the same name of the video file you selected? Some players open them automatically and it's very convenient. I'm sure there are other cases like that.
Just because it can't cover every single case and application doesn't mean it isn't worth using it for those where it fits. It's an interesting question how far one would want to go to support these special cases, because doing so adds complexity to both code and the things the user has to understand, but the nice thing with an open system is: we don't have to use it for applications that don't fit the model very well or can allow exceptions where needed.