Don't be so sure about those porn guys - big names like Mandingo and James Deen are only maybe 5'7" at their tallest. Ron Jeremy was <5'6" at his tallest, and Castro might not even be 5'5". A lot of the 'huge' dicks in porn are really big dicks on little guys.
So I wouldn't envy those guys for their natural physique. While the subject has been driven in to the ground, many women don't really care that much about your dick, and those that do mostly just don't want tiny or huge. On the other hand, there are plenty of women who are less attracted to short guys. In other words, the majority of men were dealt a better hand when it comes to attracting women than your average porn star. Ironic, eh?