She is SUPER obnoxiously pacifistic... She banned summoning magic not because it's dangerous... But because her illegal boyfriend summoned the god itself and not an avatar, being the "living embodiment of Altana" she's supposed to be virginal and pure and all that... Hence why Windurst is paired with the Yagudo, both have their leaders believe that they are physical goddesses.
So instead of just banning the blood priced true summoning... She goes and bans all summoning magic.
She also is crippled by her lost love... So much so that all she does is whine and moan throughout most of the Windurst plot...