There is a large pool of people who think that they are programmers, but are not. This is exactly what the infamous fizzbuzz test was intended to weed out. I personally know a top notch recruiter who credits her success due to learning early in her career how to filter most of the junk out. For example a "Perl programmer" who listed Microsoft Word as a skill was probably not worth looking at. (Note, this is an example from 20 years ago. But the principle remains.)
If you create an engineer focused site and DON'T find a way to segment engineers by ability, you'll find that your negotiating power is based on the average of your candidate pool. Which means that you'll discover why traditional recruiters kowtow to companies and not the other way around.