What questions exactly is the article asking? So far as I can see it's concerned with two issues: whether paedophilia is innate or learned behaviour; and whether children can consent to sexual activity with an adult. Have I missed anything there?
Answers to the second question are likely to be divided based on whether one is victim or perpetrator. I'm not at all sure about studies showing some children who feel they consented and weren't damaged by the experience, but I can't turn round and say "That's bollocks" because I'd be denying those children the opportunity to speak about their own experiences. That said, I do think it's bollocks, because children don't have the mental sophistication necessary to fully understand and agree to adult sexual activity. If we were to claim that they do, then we're in pretty dangerous territory: a paedophile could potentially use as their defence the "fact" that the child consented, and if rape cases are anything to go by it would then be down to the child to prove they didn't. And that's a horrifying prospect.
As for whether paedophilia is learned or innate, whatever the answer to this may be, I feel the article raises a valid point in its final two paragraphs. If attraction to children is learned deviant behaviour then it requires treatment, and its origins need to be studied so that it can be avoided in the future, but labelling those with that tendency as monsters means they'll likely avoid treatment for fear of the stigma, and are thus more likely to offend. If an attraction to children is innate, then demonising those who feel it is simply cruel, as they aren't able to change their orientation towards children. In neither circumstance is it appropriate or helpful to simply label paedophiles as monsters.
There was a Telegraph article in response to this one, that basically said "The Guardian supports paedophiles! They're monsters!" Now that was unhelpful. The Guardian article makes a clear distinction between having an attraction to children, and acting on that attraction. As a victim of paedophilia, I find this approach remarkably refreshing. All too often, in an attempt to make me feel better about my past, people have referred to my abuser as a monster or an animal. He is neither. He's a human being, capable of making rational decisions and weighing up their consequences. A tiger can't be blamed for biting off your arm, it's just being a tiger and doing what tigers do. But humans are different, we have the capacity to think first and adjust our actions accordingly. When a paedophile is labelled a monster we deny their humanity and so deny the very thing that makes them responsible for their actions.
I don't know whether my abuser is attracted to small children because he was born that way, or because of events in his life. I do know it was his own free choice to act on that attraction. As a victim, I would have found it immeasurably helpful during the healing process to have that distinction between attraction and action widely recognised.
Sorry, that was a bit long and rambly!