Fire Emblem from what it is worth is a game about tension. It is stressing that you are a somewhat limited force fighting a larger force and that you have to be careful when attacking so that you don't lose a unit. I enjoyed the moments where you cringe when you see a critical hit to your units, you are retreating a unit with one health while covering their flank the best you can. The moments where you breath a sigh of relief that you got everyone through a tough mission. There isn't any risk/gain when you can rush your characters to their deaths and the next mission everyone is like the black knight, " 'Tis nothing but a flesh wound!"
Play it how you want to, if the option is there it is all about your preference. But perma-death isn't technically the hardcore difficulty for Fire Emblem, it is just playing it like it originally was. And as the game developers wanted to make a game that would appeal to a younger market that don't like perma-death. Strategy games are usually about the hard choices, if you don't like them having tension they just may not be for you.