@carloslebaron,
Nobody is interested in denying the historicity of Pythagoras, for some odd reason... :-) Seems they don't care much about mathematics... But they care, oh yes how deeply do they care for sweeeeet sweeeeet baby Jesus... Their heart aches when they think of Jesus, and they are ready to write long long posts about him, how we don't know if he ever existed, how he was a ridiculous punk, how the whole world had to suffer under the "leaded shroud of Christianity" as a result, and all that.
But who cares for Pythagoras' existence? Who asks whether he lived or not, whether he was an asshole or not, or whether the world is a better or a worse place as a result of his existence? Sadly, no one. And that's really too unfair for poor poor Pythagoras...