Tywin, excellent comment regarding the mistakes of the parents. That is why I don't hate GRRM's teenagers. I just don't find them as interesting as most of the adult characters. Don't get me wrong, I do not hate Robb. I was shocked by the Red Wedding. I was sorry to see Robb go. I did not, nor do I now, want Tywin, Joffrey, or Cersei to win.
Tyrion has a thought, when meeting Oberyn, that I'll paraphrase "We are all still fighting the conflicts of our parents."
If Aerys II had wed Rhaegar to Cersei, if Brandon was not so hot headed, if Rhaegar had taken power before Jon Arryn raised his banners, if Lyanna had not died... If only Eddard could have told Catelyn, Robb, and Jon about Jon's parentage, then Catelyn would have loved him more, Robb might not have married Jeyne, and Jon might not have taken the black. Of course, Robert probably would have killed Jon if he knew Eddard was not his father.
I've posted this elsewhere, years ago, but I contend that Eddard did not live up to the words Winter is Coming. I believe that he failed to adequately prepare his children for the hard times. Yes, he gave Robb the best military, judicial, and economic education that the North could afford, but Robb needed some lessons in southern politics, especially in the bedroom.
Sansa also lacked any practical education. All she learned were fairy tales. It's awful, but she was complicit in her father's death.
On the other hand, Tywin Lannister, that heartless manipulator, taught two of his children the harsh realities of life. He coddled Jaime and Jaime was stolen away. Cersei and Tyrion may not have had a choice to be political animals, but you cannot say they were not prepared for it. Cersei just does not have the wisdom to see her limitations. But both of them know the realities of politics, "You win or you die." Both of them know about bedroom politics. Neither of them kill for honor, only for expediency.
I understand that in a perfect world you'd never have to tell your children to beware of treachery, whores, liars, rapists, murderers, and lions. But Eddard of all people knew. He knew Rickard. He knew Brandon. He knew Lyanna. He knew Elia.
I understand that Eddard loved his children and wished them joy. The problem is that there are many people wishing them harm. Eddard knew Gregor. He knew Tywin. He knew Aerys II. He knew the Kingslayer.
I admire Eddard. He strove to live and die with honor. He never sought vengeance upon innocents. He protected the weak, the orphans, and the widows. He loved his wife, his children, and his friends. He rewarded loyalty and punished treachery. He kept his oaths. He kept the promise to his dying sister... If he'd shared that promise with Catelyn, Robb, and Jon, he might still be alive or they might all be dead.
I believe that one promise kept him from fully preparing Catelyn, Robb, and Jon from the coming winter.
Tywin, also a great point regarding Robb as a safety net for his siblings. Bran was the first to suffer for the mistakes of Eddard and Catelyn, but Robb paid the ultimate price. Now Bran, Sansa, Rickon, and Arya are scattered to the winds. Arya was more interesting than Sansa up until she left Westeros... now I find Sansa much more intriguing. Players interest me more than ninjas.
Just my two cents.