I don't think there's a crystal clear answer, but probably several factors: - Each swing is a huge percentage of the actual gameplay and can have a major impact on the whole event. - Golfing takes a lot of concentration, to which silence is arguably more conducive. - The individual nature of the sport - you can affect one guy and he's the only guy, not a part of a team - You're very, very close to the player and to the action, and some might say that commands more respect to the player - The game is entirely merit-based in terms of pay. Yeah, guys do have endorsements and such, but they don't have a salary that they get regardless of how they play. One swing can mean tens of thousands of dollars, or more. EDIT: I'll also throw in that all of the factors have led, over time, to the tradition of spectator silence, which the players have become accustomed to. More as an effect than a cause, as well, is that it's more of an all-or-nothing thing, where if one guy is clicking a camera outside of relative silence it can be very distracting, whereas if everyone was making noise all the time it wouldn't matter as much.