Personally I feel the damage from breaths are adequate if you compare to the other dragon attacks.
Characters in 4ed are not the bag of HP they could be in 3.x, specially the defenders used to be (barbarians and con fighters come to my mind).
Monsters tend to have loads of HP and characters tend to do more damage in general to keep the actions interesting.
In our fight with a white dragon we almost wiped mainly becuse the freaking breath weapon was rendering us slowed and weakened frequently. On top of that the dragon defenses were outstanding for our level (it's complicaded to hit someone with a 18 AC if you have +5 bonus).
Anyway I felt that the breath was annoying becuse:
1 - weakened us frequently;
2 - if you add all the damage he was doing in 3-4 party members you will reasise its way more tham his melee attacks would do;
3 - there was no AoE healing for us.
If you really dislike the resistances, you could make all dragon attacks "penetrating" like the older red dragons. But keep in mind it's not the breath problem. Consider this before messing up with that: certanly the designers took resistances into account when they wrote thise ancient beasts.
Characters in 4ed are not the bag of HP they could be in 3.x, specially the defenders used to be (barbarians and con fighters come to my mind).
Monsters tend to have loads of HP and characters tend to do more damage in general to keep the actions interesting.
In our fight with a white dragon we almost wiped mainly becuse the freaking breath weapon was rendering us slowed and weakened frequently. On top of that the dragon defenses were outstanding for our level (it's complicaded to hit someone with a 18 AC if you have +5 bonus).
Anyway I felt that the breath was annoying becuse:
1 - weakened us frequently;
2 - if you add all the damage he was doing in 3-4 party members you will reasise its way more tham his melee attacks would do;
3 - there was no AoE healing for us.
If you really dislike the resistances, you could make all dragon attacks "penetrating" like the older red dragons. But keep in mind it's not the breath problem. Consider this before messing up with that: certanly the designers took resistances into account when they wrote thise ancient beasts.