After a 2nd reading of your post I edited my reply - but there is a damn good reason for Mountain, Jofferey and Ramsay being the who they are...
both Mountain and Hound had fucked up childhoods comming out of a fucked up family
Jofferey's father couldn't hide being very disappointed and not interested in his heir
Ramsay... without dropping spoilers, learned to be the person he is, similar to the way John Snow learned from Ned
The Hound had it worse than the Mountain because of the Mountain! Despite being distasteful at times, the Hound is a man of some considerable honor. He has done many a noble thing. He is the definition of a loyal dog. The Mountain? Shit, just read what dude did during Robert's Rebellion. He is evil.
Your Jofferey argument doesn't hold weight when you look at his siblings. By all accounts, they are wonderful kids. Joff is the anomaly. Dude is evil.
Ramsey has the bastard thing and his pop's is something else, but even his pop says that dude is too much. As left as the Bolton's are, Robb made Roose one of his bannerman, so dude had something going for him. Ramsey on the otherhand, evil.