-Cullen discriminates against Dwarves and Qunari because when he criticized them in past games for being heathens he was talking about their race and not their religion. Obviously.
-Cassandra discriminates against mages because they killed her brother. However, you can bypass it if you kill a X amount of dragons, golems and ogres, and you choose to save the Divine and kill the Knight-Commander in the Val Royeaux quest.
-Dorian discriminates against Humans because he's rebelling against the Tevinter norm and thinking of what would scandalize his family the most. Bonus points if they are not mages.
-Sera discriminates against Humans, for being nobles and thus don't understand the plight of the lower clasess, and Elves, for being Dalish and thus are tree-hugging snobs that look down on City Elves.
-Solas discriminates against Dwarves because they don't dream. Otherwise, how could he stalk the dreams of his beloved and learn their deepest secrets if the Inquisitor doesn't dream? So unromantic.
-Josephine discriminates against Warriors because she considers them incapable of diplomacy, otherwise they wouldn't have chosen such a class. The only exception are Humans, because their family are diplomats.
-Vivienne discriminates against Humans, Elves, Dwarves and Qunari without horns, because her headgear makes it clear that deep inside she always wanted to be a big, horned Qunari.
-Blackwall discriminates against everyone except sexy female Dwarves. Otherwise, Aimo's comics couln't happen. And that would be terrible.
-Cullen discriminates against everyone because he hasn't a mature mind and Thedas doesn't have the Internet to discover the wonders of porn and fanfiction. At least they have cats.
-Leliana discriminates against everyone because they are not the Warden. That she might have not been romanced doesn't matter to a professional stalker spy.
-Varric discriminates against everyone because they are not Bianca. If he's talking about the woman or the crossbow, that's anyone's guess.
-Iron Bull doesn't discriminate because he's just that cool. And horny.