Baseball is boring to those who don't understand the game. It has a certain peace about it, it's slow enough that you can enjoy yourself at the ballpark and have good conversation but fast enough that stuff happens.
It's in-between Golf and more active sports like basketball.
So a game which usually lasts three hours and where you will definitely find a winner is more boring than a game which usually lasts multiple days without seeing a winner?
Once you come to understand and really get to know the game of baseball, you will develop an appreciation of the game that makes it anything but "boring"..