His choice of the word "faith" doesn't proclaim a religion or acknowledge atheism is itself a religion in any way shape or form.. He's using YOUR work that you can relate to.
I've never seen an atheist raise money for their religion.. or proclaim.. You must send me 10% of the everything you make or you're not REALLY a (choose religion here).. so there's that basis alone for atheism NOT being a religion.
Not every religion requires money-raising. However, belief that something is true without proof something is true (and, frankly, with the full comprehension the belief simply cannot be proven) is faith. Science is like that, in that the origins of life are unprovable, as is the origin of the universe (unless we can start with nothing and create a universe without actually doing anything that would imply some kind of intelligent design, and we can do that repeatedly for peer review and accuracy of the proof).
So, no, lack of raising money (I've seen a lot of scientists beg for money, by the way) is not a proof of lack of "religion", but faith in the unprovable seems like pretty conclusive proof of religion status.
What you should really ask, and what I think is very important in our days, is why would an atheist be insulted by a cross on Federal Property.. or a nativity scene on the courthouse lawn? It they are truly atheists, and not just intolerant liberals, the cross can't be insulting to them.. nor can the nativity scene as neither has any meaning to them..
What is a cross to an atheist, and how would it relate to something they wholly don't believe in??
I fully get that - they have been sold a load of goods about a mythical separation of church and state. They think that if the state offers space, or electricity, or purchases a religious artifact than that breaks the mythical separation. They've either never read the Constitution, or can't distinguish between the First Amendment and the myth of separation.
Given their lack of comprehension, it makes total sense. They're not bothered by the cross, or nativity scene, they're bothered by their tax dollars being used in some way to support the majority opinion. It's like the people bothered by fluoride in their drinking water - they're not afraid of the fluoride, they're afraid of a government that can drug them without their knowledge or consent.