The word 'probably' is key. That means they don't have the evidence to say 'there's absolutely no God'. And because they don't have the evidence they're working blind.
It's been pointed out to you in this thread at least once and you seem to be missing it. Scientifically speaking, you cannot prove a negative. It is impossible to prove that no gods exist, just as it is impossible to prove there is no planet somewhere else in our universe that is exactly like ours in every detail (same plants, animals, humans, etc).
You cannot prove a negative.
Despite this limitation of not being able to prove negatives, science continues to progress by leaps and bounds. So much for "working blind."
Tell me this: is there anything that affects our reality that we as humans generally accept without a shred of empirical evidence, other than religious ideas? I can't think of any. The fact that we are expected to make an exception when it comes to religious claims is a perfect example of the "special pleading" logical fallacy.