Not sure if this is the right tag / category, sorry for that, feel free to move to feature request if it fits better there.
The output of gpg --delete-secrete-keys and similar without name is confusing:
$ gpg --delete-secret-keys gpg (GnuPG) 2.2.4; Copyright (C) 2017 Free Software Foundation, Inc. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. $ gpg --delete-secret-and-public-keys gpg (GnuPG) 2.2.4; Copyright (C) 2017 Free Software Foundation, Inc. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. $ gpg --delete-keys gpg (GnuPG) 2.2.4; Copyright (C) 2017 Free Software Foundation, Inc. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
Would it be easier on the user to write a small message saying that a user name is required rather?
Results obtained on Ubuntu 18.04:
$ gpg --version gpg (GnuPG) 2.2.4 libgcrypt 1.8.1