“I didn’t get any Greek and Roman gods in, because at the time I couldn’t convince myself there was any particular reason to bring Greek and Roman gods in. Now, a few years ago I read about the discovery of some ancient Roman coins in the mud of the Ohio River, and they’re definitely ancient Roman coins. There are differences of belief as to whether they were coins that somebody hid there and they got lost or whether they date back 2,000 years. But I don’t need any kind of proof on this. All I need is to be able to point to something in the way I could point to the Egyptian stuff. Now I have something that I can hold onto and go, “Well, there is a case now for ancient Romans knocking around America which gives me the whole panoply of Roman gods, too.”
Having said that, the other reason I never used them was at the time I felt they were overused, and I like the idea of using ones that were a little bit underused and was proud of myself for having done so.”
So is Neil Gaiman saying that, though Greco-Roman gods are “overused” they are not as popular as the Norse? The fact there would be no appearance of them in American Gods seems to imply that Americans don’t favor them as much as Norse–that they do not have as many worshipers to make them relevant or prevalent. Which is illogical due to the the fact that 1) we know more about the Greco-Roman myths and 2) the entire West is built upon or around their mythos (philosophy, the Arts, arguably Christianity). So the reason they aren’t seen in his book seems to imply something about their status. The biggest fan base for Norse myth stems from the comic book craze (read: Thor). I still wouldn’t say it overshadows the following of Greco-Roman gods, though.
It seems like a weak argument — something overlooked when he was trying to build a mythos. He may have highlighted some marginal gods, but at the cost of his mythos.