You are getting hung up on the paedophile case .... but if enough men wore dresses (kilts) it would no longer be considered abnormal ... which is my point ... and logically if enough people engagef in abuse ... that logically could no longer be considered abnormal ...
Which get's us back to your original question .... how as individuals and as a society do we judge and determine these issues ... through research, knowledge and logic ... or by a bias which is the result of the accumulated wisdom of generations of humans living together ....
The human condition is such that the complexities will always throw up issues that confuse and frustrate both logic and folklore .... I think both sides of the brain need to be used on ocassions ...
As to who makes the decisions .... what if the person deciding is a highly functioning sociopath with nil empathy ... or an emotional wreak paralysed by over empathicationism .....