Temperment problems can stem from breeding and the way the dog was raised.
W4B, you just mentioned the classic "heredity versus environment" argument - but with different words.
And I agree with you.
I call Labrador's - 'ford dogs.' They're incredibly easy to train and predict when they come from reputible stock and properly handled/cared-for/trained.
Labs love to please their people and one has to 'work at' creating a failed [hunting] Labrador!
But as for biting, I'd also question if the bites reported are a reflexion on the total number of Labradors in the country.