>I don't know any scientists or engineers who would be willing to sign on to this kind of bigotry

I guess you don't know many engineers, or you only know software engineers in Silicon Valley or something. Engineers, in my experience, and especially the non-software kind, tend to be extremely religious. In fact, studies have found that many middle eastern terrorists come from engineering backgrounds. The engineers I've worked with have been overwhelmingly conservative, and frequently religious. (Those that weren't conservative were usually libertarian.)

Yeah, your typical Millennial programmer in the Bay Area probably isn't religious at all, but hang around some 40+ mechanical or electrical engineers and you'll see an entirely different crowd, with probably a lot of Trump supporters.

We've probably encountered a different engineering demographic. But it's not just a question of being religious. Would the religious engineers of your acquaintance say that unbelievers are incapable of being the best kind of citizens, by virtue of their lack of belief in the supernatural? That's what the Boy Scouts say.

I haven't asked any that particular question, but I see no reason to think that many religious people, engineers or not, would answer that they believe that unbelievers are incapable of being the best kind of citizens. That's a pretty normal kind of belief for religious Americans really.

I suppose you're right, that this kind of bigotry is commonly considered acceptable among believers. I know more scientists well than engineers. Even the ones who are Christians would be appalled by the Boy Scout Principle.