Here is an example proof-of-concept thingy of using Kirby users as children of the authors page.
Panel access:
user: admina@test.de
pw: testtest
Check out the AuthorsPage model in /site/models/authors.php
Note that the code is lacking some checks like if a page exists etc., so please regard this as quick and dirty.
This allows you to define authors with permissions and nevertheless have author pages without using routes. The fields (actually only the email field in this case) for the authors are made readonly to not mess with the user content.
Also, you would have to fine-tune the blueprint options for the virtual children etc.