In the name of the Warrior, I charge you to be brave. In the name of the Father, I charge you to be just. In the name of the Mother, I charge you to defend the innocent. Arise, Brienne of Tarth... A knight of the Seven Kingdoms.
If you were to marry Cersei, she's murder you in your sleep.
The King shits and the Hand wipes.
Not everybody wants to die for someone else's home