I'm pretty sure that's just a windows thing. I use ubuntu, and the file manager displays a file extension. Why is the file no extension? Usually that means either a directory or an executable binary file. DOS (and the windows terminal emulator) use file extensions, but executables use .exc. How would you know what kind of file it was without running it? (you could open the terminal emulator, but how with GUI)
What is a whippersnappers?
EDIT: In some places, firefox removes the TLDN from a domain name. Are the problems caused by removing the file extension similar?