When CTR began his ministry, he saw his role as gathering together the few true Christians distributed throughout the churches of Christendom. Although that mission has expanded over the years, especially under Knorr, it would not be an error to say that JWs see their role as gathering together "god-fearing, god-loving" people from all the religions of Babylon the Great to the true worship of the True God who lives in a desk drawer in Brooklyn. So today's JWs will talk with Jews, Muslims, Taoists, Sikhs, Buddhists, Santaria-ists, practitioners of Voodoo, Mormons, Hindus, Sufis, B'hai, -- anyone who shares their basic belief in invisible people. Maybe not scientologists though.
The JWs response to the announcement "I'm atheist" is not that uncommon. Witness (pun intended) the reaction of some here on JWD to the same declarative sentence. Yikes! You'd think someone just painted their dog green or something.
I have been surprised even when talking with medical professionals that when they ask "religion?" and I reply "atheist" there's a momentary lull in the conversation, as though I had just uttered the unspeakable oath.
It's fun.