I think that the parents and shit probably went through just as hard of times as the kids have been through. Look at Kakashi, remember what he said to sasuke before sasuke left on his revenge thing? he talked about how that everyone he ever cared for was dead and gone- he got his sharingan in weird way so he must have been through some messed up shit. Also look at the lady that oro bit that has the cursed seal- she was one of the jounins doing the chunin exams- she had to go through some bad stuff if shes been with oro or even just got bit with that seal- we see everything these kids go through, so we are just going to automatically think they'll be stronger and better, but i think its not so much out of the norm for a ninja- just my 2 cents