There are two forces at play in politics and belief, without naming the sides in typical fashion, let's just say one is on its extreme is being driven by "hope" and the other on its extreme "fear". If you go too far into either of these its a problem, the goal should be to be centric and based on reality. This reintegrating of ISIS jihadists, to me is the swinging too far to the "hope" side. Hope is a beautiful thing and we should always temper it with some level of realism. Its the same with fear, fear can lead to terrible things with humans and atrocities, still, a realistic, healthy amount, should be involved in your policy.
For instance, maybe you are living the fantasy land of Narnia if you think you can just hope away the fact that these ISIS fighters cling to extremely ignorant and dangerous ideas completely at odds with all of our western values, then proceed accordingly.