I don't know how scientific journals manage to exist but technically it could be as simple as a link to the user page on the university professors profile page.
There are also plenty of pseudonymous Wikipedians with credentials that they keep secret or vague. As long as they don't edit pages where they have an undisclosed conflict of interest, that's also fine.
Credentials can lend someone credibility in discussions. They just don't grant special editing privileges.
If an editor is an expert in a field and you can verify it it would be most useful to the encyclopedia to treat them as such. This is not actually a special privilege but how people normally do things.
I can gather citations and glue them into an article but someone with actual expertise knows which parts are important, what isn't and what is missing.
Wikimedia is of course free to have an encyclopedia project to entertain children with to much time on their hands but they will continue to lose good editors. You can't have both.
If you disarm the man before throwing him into the alligator pit he won't survive but it will be great for the alligators.