Current key files are stored in filenames more or less like: id_rsa (private key) id_rsa.pub (public key) Generally, users only need to interact with the .pub file, but tab completion will choose the private key file by default, resulting in user errors that compromise key material. It might be better if new keys were created with an extension indicating that they should be kept secret, such as .secret (do they have to be 3 characters still?)
This has been the convention since dawn of time. I think it will cause a lot more problems than it solves.