Yes, I know, to some ALL Golf is boring. But that aside, why is the British Open so dull on TV? I believe its for three reasons:
1) "The Open" is played on Links courses which are tree-less, have almost no water hazards, lack ocean views, dramatic sea-side cliffs, and sparkling white bunkers. As a result, almost every hole looks the same on TV, and its often hard to see whether the balls on the fairway or the green.
2) The Camera work seems inferior to that in the USA. Where as US TV gives you a myriad of shots from various angles and gets "Up close and personal", "the Open" provides far too many wide angle, distant shots of the players. Its difficult to get emotionally involved. At the Masters you seem to be right next to Tiger as he plays the game, while at the British Open it seems like you're seeing all from 60 feet away.
3) Its usually grey and either misty or rainy, which means everyone is bundled up and hard to see and differentiate one from another.