Obviously, I have a few thoughts on this.
First, I'm not sure "fault" is the right word. But the fact is that the two starting pitchers have an inordinate effect on the game when compared with anyone else involved. Although, the two quarterbacks are unquestionably the most important players in a football game, I don't believe their influence is quite as great as that of the starting pitchers in baseball. For example, the head coaches/play callers in a football game have a huge effect, while the influence of a manager is negligible. I would suggest, however, that the influence of the quarterback has grown while at the same time that of the starting pitcher has lessened.
Beyond that, we should examine the statistic we call "Win-Loss Record" for starting pitchers. Contrary to popular belief, this statistic is only incidentally related to the W/L record of the specific team the pitcher is on. It is a statistic that, like many other statistics, features arbitrary criteria. In this case a minimum of five innings pitched, a lead upon exiting the game, etc. For some reason, people are disturbed by the arbitrariness of this statistic while ignoring the vagaries of something like, for example, batting average, which does not actually measure how well a player hits the ball, but rather his luck in where it happens to land.