[nofearinc]

A few ideas:

1) A public list of recognized job titles (think of an employment bureau catalog or else) that defines the job description by an authority. At least a reference that most would pay attention to.

2) A unified training program for each branch (or developers in question) outlining the required skills or targets for developers

3) A WordPress.org profile that showcases the work in a better manner - think of a GitHub/LinkedIn version in the WordPress context

I also wouldn't necessarily vouch for a licensing program (probably commercial/financial interests), but some standardization and guidelines could help immensely and solve various problems for employers, clients, expert and beginner developers, site builders, even users.