How is that so ridiculous?

Because 4 runs in 6 innings is a rate of 6 per game.

No team averges 6 runs per game (except maybee the Yankees, and I'll be surprised if even they average 6 RPG by the ens of the season).

When you give up 6 runs, you lose maybe 75% of the time.

Zambrano gave up runs in this game at the rate of 6 per game.

He deserved the loss.