Maybe Americans don't have the patience for a game that lasts as long as cricket does. It can be difficult to comprehend how a test match can last five days and (sometimes) still not have a winner.
Even a fifty over match lasts nearly eight hours if you include the dinner break, which is more than twice as long as a game of baseball. That's why attempts to get Americans interested in cricket are based on the T20 format of the game.
As a proud supporter of the South African cricket team I don't know anything about baseball, so I can't comment on which is the better game.