He is not full of pride when he tries to gather others from Orgrimmar, he just feels it a must ! Thrall knows his people more then any other orc! He would not be corrupted by Pride because he learned lot in his journey with the Aspects. He found total calmness within himself, a new power (I cant recall the name of the Power he found) within him. Novel "Trall - Twilight of Aspects" is all about Thralls mental growth and becoming more calm and emotion controlled character. In the beginning of the novel he cant meditate with his fallow Shamans because he is filled with emotions and in the end he is capable to be in the place of Earth Aspect in the Ritual. He Mentality has grown very strong, so he will not be effected with Pride. There is one single Sha that can effect him - it is Fear. Garrosh holds everything he holds dead in his hands - his people and Horde (trolls and Tauren especially), Garrosh might take Aggra and his child (like in Hollywood films LOL ). Horde and his family is all Thrall loved and cares crushing them might frighten him so....
---------- Post added 2013-04-27 at 11:58 PM ----------
So ? What is Negative there about Thrall? To stop Alliance member (jaina) from destroying Orgrimmar? From stopping her going completely mad? Or that he has become "different" ?