What would you choose (an example):
- Having a father from the start, having awesome time with him, but after 15 years, he dies in a car-accident.
- Being alone from the start.
I know both are TERRIBLE, but the first one is less painfuller... At least you knew love.
It seems you are trying to mitigate Itachi's pain. He didn't lose his family in a freak accident, he was forced to murder them so at least one could survive, then be hated for it, even though he was innocent. Go into exile, and turning his one and only remaining loved one into a emotionally damaged child, making him hunt him down and kill him. That isn't even the whole story.
And allow me to pose my own question. Which is more painful?
-Being born without an arm
-Having an arm and have it ripped of
Clearly, as Sasuke pointed out so long ago, we suffer because of out bonds. Having a bond and losing it, is more painful than never having one to begin with, because you can never feel the pain of losing it. Also, the pain from losing that bond can increase or decrease, depending on how it is lost. For example, having a love one be murdered is more painful than them dying from old age. Sure Naruto may have been suffering for longer, but that doesn't mean he has been suffering more.
And then there is the final nail in the coffin. The fact that he is an Uchiha, who naturally loves more and will feel more pain when the one he loves is lost.