What if your file system didn't distinguish between underscores and spaces, your GUI displayed them as spaces, and your command line displayed underscores? The

What if your file system didn't distinguish between underscores and spaces, your GUI displayed them as spaces, and your command line displayed underscores? Then this problem goes away entirely and you instead have the problem of not being allowed to have "this_file" and "this file" in the same directory. A problem which probably doesn't matter.