I came across this very interesting quote, but it is giving me some confusion. Since Russel was a philosopher I thought it was best to come to the Philosophy stack exchange. And this is by no means a religious debate, or a debate of Russel's logic, I just want to understand his perspective. Though, I guess if you want to give a little of your opinion, that's up to you.

“As a philosopher, if I were speaking to a purely philosophic audience I should say that I ought to describe myself as an Agnostic, because I do not think that there is a conclusive argument by which one can prove that there is not a God. On the other hand, if I am to convey the right impression to the ordinary man in the street I think that I ought to say that I am an Atheist, because, when I say that I cannot prove that there is not a God, I ought to add equally that I cannot prove that there are not the Homeric gods.”

― Bertrand Russell, in Am I An Atheist Or An Agnostic? A Plea For Tolerance In The Face Of New Dogmas (1947 or 1949)

Why would he say to the man in the street he was an atheist? If he believes he can produce no evidence for any god(s) of any religion I don't see why this makes him change to having the belief that there is conclusively no god(s). Is he implying that because there are so many religions that they all must not be true?