Bull will acknowledge all TV aren't the same. He says that the inquisitor isn't one of the ones he hates in Haven, for instance. And then I always say my merc band was mostly TV just to mess with him and he'll grumble and say it's better than being bandits. He's stubborn about it, but he gives a little here and there. He equates Tal-Vashoth with what he saw in Seheron, and honestly, they did some pretty heinous stuff, so I'm not sure I can blame him. Besides, his job was hunting them down. It's always easier to see the enemy as a monster. Bull mentions in a banter with Cole that he has a trick for making people not people, so I always figured it was more of that.
I really think the difference between him and Fenris is that while both have have their issues, only Bull is afraid of actually becoming what he fears. Fenris has seen the dark side of magic, but that's as far as it goes for him. He has no real worry of ever having to actually face that temptation and succumb. If you take him into the Fade, it's a real wake up call. (or he blames Hawke, if I recall, when in a rivalry) Bull, on the other hand, has probably been taught all his life that any path outside of the Qun leads to exactly what he's afraid of. I forgot about Fenris' eventual acceptance of Bethany. (Most of my Hawkes were mages) but that's a good point, but aside from Adaar, Bull doesn't have much experience with TV outside of Seheron.
I'm not trying to argue anyone's opinion or what they took from the game. This is all just my view on it.
ETA: Agreed, though, on one last conversation to wrap things up one way or another. Could have been done after another round with the stick or something.