I think you're exaggerating the durability of werewolves, most people don't play the game at level 81, I imagine you play the game with maximum armor rating and with 700-800 health.
There are so many situations where it's impractical to use beast form, against dragons, against strong archers, against high level mages etc. I imagine your response is to just rag doll them, but you take a hit from each of them each time you fight, when you're against 4-5 other human enemies you don't have time to heal.
Dragons will absolutely wipe the floor with wolves, no way to heal, you can't force them to land, completely impractical. Especially since ancient dragons bite for 300-400+ damage on master with no armor, I dread to think how hard legendary dragons hit.
I use normal armor ratings. Anything above the norm makes the game too easy. I use my level 81 guy as an example because its my favorite character, but I used my level 51 character for both vamp and werewolf. I saved before excepting the gift from Harkon so I could do both. Anyway, it was even more effective at my level 51 character, and on a brand new character i'm currently playing, since the damage output is the same, and the npc's levels are lower. So if anything, it would be harder to play as a werewolf at a high level, not easier. I will admit that for dragons, I need to take away aggro with the two summons, but so what? The dragons never hit me while its worried about them, and at the end of the day, the dragon is still dead and my werewolf is still victorious. At level 81, my health is around 700, but my health is always high for my level, since I always play as a warrior, so that wouldnt matter, plus the bonus health u get as a werewolf is added too, and thats for everyone no matter your level.