TitankiinToxikyleThe Thu'um is magic though.
But It shouldn't be. It is a power, not magic. So you are saying that werewolves can't hurt mages when they use Wards?
The Thu'um is a form of magic.
"The Nords have long practiced a spiritual form of magic known as "The Way of the Voice", based largely on their veneration of the Wind as the personification of Kynareth. Nords consider themselves to be the children of the sky, and the breath and the voice of a Nord is his vital essence. Through the use of the Voice, the vital power of a Nord can be articulated into a thu'um, or shout."
It is not identical in nature to the magicka-based spells but it is still magic, which wards protect against.
Lycanthropy by comparison is a supernatural condition. Magic may be involved but transforming into a werewolf is in no way comparable to casting a mage armor spell or a fire cloak spell. Lycanthropy is an inner magic affecting the body itself rather than an outer magic affecting the body as an external agent, like a paralysis or invisibility spell.
Lastly it is important to separate game mechanics from lore. "Shouts are not magic because they're mapped to the powers button" doesn't work in lore discussion. "Powers" like the Serpent Stone ability and Ancestor's Wrath are still magic even though they use the powers button.