Sure. But I think of the file extension as a way to tell the OS which program I want a file to open with. In Windows when I see a .mp3 file I know which program will open when I double click on it. In Linux it's a mystery. I like my computer to behave in a predictable manner.

In Windows extensions have a meaning. In Linux, why even bother having extensions? In neither OS does the extension tell you about the content of the file. But on Windows the extension does tell you something useful about how the OS interacts with the file.