Liability is a bitch...
Most people with that kind of experience know someone that would gladly sign them off as well tbh...
That is true in my case. Most of the recreational C-cards I have were signed off by instructors and agencies without taking a class or test. All of them knew me and/or understood the scope of my military and commercial training and dive history. I have asked friends for some cards over the years just to let boat operators off the liability hook.