This is akin to saying that human sexuality is wrong and harmful, or male competition is wrong and harmful.
It is taking a purely evolutionary phenomenon and assigning it a nebulous moral value. Religious behaviour is a direct result of natural selection. Comparable phenomena include homosexuality and extra-marital pairing. As scientists, we cannot make value judgements on these natural phenomena. If we do so, we must clearly leave the realm of science and enter the realm of advocacy.
This is akin to saying that human sexuality is wrong and harmful, or male competition is wrong and harmful.
logical falacy: is != ought
As scientists, we cannot make value judgements on these natural phenomena.
The evolutionary explanations for the origin of religious behaviour is entirely irrelevant to the question of whether the claims made by religions are true. Religions make testable claims like the existence of miracles, science can be applied to these claims. More broadly, Dawkins uses a scientific approach to make a very strong argument that religions are not accurate descriptions of reality.
Religion is wrong in the sense that it is based on incorrect assumptions, namely that God exists. This is not a moral statement. Whether or not it is harmful is to be decided by the evidence (many terrorists are religiously-motivated etc.), and I agree this point is harder to establish, because religion also brings comfort and so on. Anyway for Dawkins this issue seems secondary to the first one.
As for your second paragraph, but of course this is advocacy! Dawkins is not acting as a scientist here, I think this much is clear. He is an advocate who draws on his scientific knowledge and his rational philosophy to make his case.
This is akin to saying that human sexuality is wrong and harmful, or male competition is wrong and harmful.
It is taking a purely evolutionary phenomenon and assigning it a nebulous moral value. Religious behaviour is a direct result of natural selection. Comparable phenomena include homosexuality and extra-marital pairing. As scientists, we cannot make value judgements on these natural phenomena. If we do so, we must clearly leave the realm of science and enter the realm of advocacy.