Why do Bible critics get so annoyed about the Gen.30:37ff account of Jacob trying to "help out God" by....?

It's too bad no one has bothered to read the remainder of this account. They would have discovered that it was not because of any belief in magic sticks that the livestock was born speckled or streaked. It was because God moved against Laban in judgment. Go read chapter 31 of Genesis and learn why the livestock became Jacob's.