Scientific data does not support the opinion that pedophiles cannot be treated. But the research on this topic is horrendously ill-defined. The definition of "children" ranges from infant to 18; the definition of molestation is just as vague.
In some cultures, mothers stroke or suck the penises of their infant boys to soothe them. In other cultures, mothers have their infants suck and stroke their breasts. Should they be executed?
Some cultures marry 14-year-old girls to 40-year-old men. Are those men pedophiles, incapable of rehabilitation, who should be sent to the gas chambers?
What type of parents are exposing their children to pedophiles? Only 5% of "child molesters" are strangers to the family. What are the warning signs? What are the long-term effects on the victims? Are the effects of a single instance more traumatic because of the incident or b/c of the parents' reaction?
It's a troublesome issue, but one that has been vastly overstated, and conclusions and assumptions have been a leap-frog game of opinions and anecdotes.