Maybe I'm misunderstanding your argument. First off, I'm not suggesting restarting every time a character dies; I never have. My argument is that permadeath is meaningful and additive to the gameplay experience even if you choose to restart after a character dies (or even if you do so every single time a character dies). The reasons for that belief have been covered at least a dozen times in this thread so there's no point in stating them again.
What irritates me is people who claim or seem to suggest that restarting upon a character's death is "doing it wrong." There is a lot of that in this thread. The thing is, all of the people who are making this claim have never actually finished Awakening on Classic or any previous FE game without restarting at least a few times upon a character's death. At the very least, I've yet to see anyone make the claim that they have. Maybe a few have done it in Awakening on Easy or Normal their first time through but other than that I'd say it's next to none. The reason for that is very simple, the game was not designed to be played that way, just like every game in the series. Playing through FE without restarting any chapters is more or less a master run of the game, it is not a normal way to play nor is it the traditional way to play. Anyone who has experience with the series will agree with this point.
Now, having said all that, I think Casual is great! If people don't want to deal with permadeath I'm glad they don't have to, and I don't think that's "doing it wrong." In fact, I'm thrilled the option exists because it allows more people to experience this wonderful series. I just get tired of hearing over and over and over about how restarting defeats the point of permadeath. Maybe that argument can be made in other games or series, but it is simply not the case in Fire Emblem.