I never said you cant die from the bites, I said you dont turn just because you got bit, or got some guts on you. If that were the case than EVERYONE would already be dead, blood in their eyes, in their mouth, etc.
Just because you get bit doesnt mean you die. The fever kills you.
Look through how it works I cant explain it any better
If you ALREADY are infected which Rick clearly tells everyone at the end of season 2 than what would a bite do other than give you an infection?
You only reanimate when you DIE. Rather it be from loss of blood, natural causes, infectious disease etc.
To prove the point Jim was never shown to turn while with the group, he was left to die because at the time they didnt realize once you DID die you turn and didnt want to shoot him.