The golf swing is the baseball swing is the tennis swing is the boxing punch is the basketball pass is the hockey slap shot. It is just a hell of a lot harder than any of those to do correctly. It is the athletic movement that makes golf a sport. Pure stamina is admirable but not related to the athletic movement. A professional golfer can refine the swing to a degree that allows a little guy like Ian Woosnam hit a straight drive 300 yards almost every time while Michael Jordan can only occasionally accomplish it.
I think hitting a baseball is the hardset thing to do in sports. Hit a round object, with a round implement, and hit it squarely, and it is thrown at you at ninety miles an hour from sixty feet away, and with movement on it (curve, forkball, knuckler, split-finger). The batter has milliseconds to decide ball / strike / fastball / curveball / scroogie and swing or not.
Still consider myself a beginner after almost 2 years of golf. But I do see a direct parallel to a baseball swing. Rather than keeping your eye on the pitcher you keep your eye on the ball. The swing is all about keeping on the plane. The plane changes in golf depending on the slope and depth where the ball sits. The plane changes in baseball depending on the slope of the pitch. Same principles, just a lower plane for golf. Love the game. It's intellectual, individualist, super-athletic (yes, it's all about control of every part of your body), ambitious, addictive and spiritual (in that most courses are surrounded by nature).