Good point. I remember ads in the Washington Blade saying "in shape only". Some guys have told me how difficult is to top a guy who is overweight but in some cases it's also difficult for them to reach in.
Warning, might be offensive.
Unfortunately sometimes even clients lie about their age, body, etc.
I do agree with @Monarchy79 that's is a very personal business and sometimes even on Viagra can't perform nor deliver the BFE with everybody who wants to hire them. Unfortunately some guys aren't attractive to some ethnic group, bad for business but it's their body.
Most Asians won’t hire someone who’s not Nordic for example.