Yes I could. Now would I? No. No fricking way.
The bottom line is that jump on the skateboard is accomplished with gaining proper speed and elevation.
I've been snowboarding and it takes zero skill...just practice. The jump the snowboarder does, all he does is stand on the board. The wax on the bottom of the board, the incline packed with snow provides the requisite speed and all he does is go up the ramp and enjoy the ride.
Surfing. Are you seriously saying that only a select group of people can learn to surf?
Anybody with a complete lack of regard for their own physical well-being can surf, snowboard or ride a bmx bike and do the tricks these guys do...with enough practice.
No matter how much I train, practice and/or prepare I could never run a 4.3 40, dunk a basketball, etc.
I forgot to mention, no, you really couldn't do that.
Have you ever seen women's skate competitions? If skateboarding is as you say, and the only thing you need to be successful is practice, then the women should be equally good as the men, but it is far from the case. The women can hardly get above the coping on a halfpipe, and can't even come close to the technical maneuvers that the men do in street and park skating.