I would argue that most atheists are more versed in theistic matters than most of the devout. I can say unequivocally that I am more educated in theistic matters than any Christian that I know. I can't speak much for other religions, but as So eloquently stated, many assume faith just because they've been told to do so. It's hard to question what your peers, parents, etc. have been nailing into your brain since before you were able to utter words in refutation.
For most of us (I have some different views, but that's not important), the conclusions were derived from many hours of reflective thought and research. We've heard all of this before, and most of us have considered the very things that Collins is talking about. He's free to draw his own conclusions.
Personally, I see nothing at all wrong with Collins' view. He's resolved the matters nicely in his mind, and he's free to do that. I would argue that his idea of "God" is very different from most theists. He takes on an impression of God that many scientists do, but you'll find that many use it as a more abstract representation of that which precedes the natural world they study and not so much a personal God.