Interesting thread...and I don't think this is just exclusive to surfing, but runs across the spectrum of athletics, and there could be endless socio-economic reasons behind it.
One theory I found interesting from a swim coach is that a lot of what we do athletically has to do with sensory and motor neurons. Well, what he proposed as this topic pertains to swimming is that when the epidermis is exposed more to the elements it is possible that motor and sensory neurons could become more sensitive and therefor, receptive to stimuli. When you think about it, the north (east or west) is wrapped up in layers of clothing for a much greater portion of the year, thus possibly limiting exposure to elements/stimuli and lessening the development or sensitivity of motor neurons, thereby possibly limiting or lessening the development of world class athletes. And as a disclaimer, his theory didn't just pertain to when the person is engaged in their activity/sport, he was talking about all the time (flip-flops v. sorel boots).
From a sociological standpoint, Boston, NYC, Phili, Seattle, might hold a significant population but they don't exactly have good, immediate access to "surfable" spots. I think the south (though the population centers might be smaller, and therefor perceptibly reduce the chances of a pro-surfer) probably has more easily accessible, beach side communities/cities such as Norfolk (close to VB) VB, actually the whole tidewater area, Miami, Jacksonville, San Diego, LA, which in turn would increase access) and therefor actually increasing the chances of pro-surfers. Also, I've lived on the coast now for 9 years, 3 in VA, and 6 in ME...I'd definitely say the beach is a lifestyle in VA and definitely not in ME, and would assume the same throughout the NE area as the water is much colder than once you go south of NYC.
Anyway, my ideas....
I think this is basically saying that people in the SE and SW are have faster and more efficient human development. Interesting... wink wink. Looking at you New Jersey...
So people in the south are smarter and better surfers... It all makes sense now.
Seriously though, interesting. I agree that the weather and exposure to elements stuff. That is very logical and makes perfect sense. I mean, on an even more basic level than that, surfers in the south are far more likely to show up in numbers all winter and spring just because of water temps and weather. You have to be part of the "core" group to A) go to the beach and hang out all day in February in Jersey B) paddle out for more than an hour, wrapped in rubber on a regular basis C) generally go outside and exercise.
Disclaimer: I grew up in MD and would play basketball on sheets of ice in the dead of winter. I would go running when it is 5 degrees out.. So its not that people DONT do it, its that on an annual basis, people in the south don't have to make the difficult decisions or sacrifices that they do in the north, so as a sheer numbers game, there are more people in the water and outside on an annual basis. Cause remember, even in the south the beaches get flooded all summer. Just as bad as up in the mid atlantic and NE. Just as bad. Just as many tourons on the beach. Definitely more in the water too. People will sit in the 85 degree water down here like buoys for 3 hours straight.